diff --git a/compiled/facebook-www/JSXDEVRuntime-dev.classic.js b/compiled/facebook-www/JSXDEVRuntime-dev.classic.js
index 8ef75488e7..6c0ef234f5 100644
--- a/compiled/facebook-www/JSXDEVRuntime-dev.classic.js
+++ b/compiled/facebook-www/JSXDEVRuntime-dev.classic.js
@@ -109,8 +109,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
 
     function getWrappedName(outerType, innerType, wrapperName) {
       var displayName = outerType.displayName;
@@ -1231,14 +1232,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
diff --git a/compiled/facebook-www/JSXDEVRuntime-dev.modern.js b/compiled/facebook-www/JSXDEVRuntime-dev.modern.js
index 332d026130..fed4994b37 100644
--- a/compiled/facebook-www/JSXDEVRuntime-dev.modern.js
+++ b/compiled/facebook-www/JSXDEVRuntime-dev.modern.js
@@ -109,8 +109,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
 
     function getWrappedName(outerType, innerType, wrapperName) {
       var displayName = outerType.displayName;
@@ -1231,14 +1232,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
diff --git a/compiled/facebook-www/REVISION b/compiled/facebook-www/REVISION
index d223277239..efcac2c6f9 100644
--- a/compiled/facebook-www/REVISION
+++ b/compiled/facebook-www/REVISION
@@ -1 +1 @@
-6090cab099a8f7f373e04c7eb2937425a8f80f80
+48b4ecc9012638ed51b275aad24b2086b8215e32
diff --git a/compiled/facebook-www/React-dev.classic.js b/compiled/facebook-www/React-dev.classic.js
index b9d62d12e7..2afafcfb99 100644
--- a/compiled/facebook-www/React-dev.classic.js
+++ b/compiled/facebook-www/React-dev.classic.js
@@ -24,7 +24,7 @@ if (__DEV__) {
     ) {
       __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error());
     }
-    var ReactVersion = "19.0.0-www-classic-308d9210";
+    var ReactVersion = "19.0.0-www-classic-b9e0eea7";
 
     // ATTENTION
     // When adding new symbols to this file,
@@ -475,8 +475,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
     var disableLegacyMode = false;
 
     function getWrappedName(outerType, innerType, wrapperName) {
@@ -1639,14 +1640,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
@@ -1906,7 +1910,11 @@ if (__DEV__) {
 
         var defaultProps;
 
-        if (element.type && element.type.defaultProps) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          element.type &&
+          element.type.defaultProps
+        ) {
           defaultProps = element.type.defaultProps;
         }
 
@@ -1926,7 +1934,11 @@ if (__DEV__) {
             // backwards compatibility.
             !(enableRefAsProp && propName === "ref" && config.ref === undefined)
           ) {
-            if (config[propName] === undefined && defaultProps !== undefined) {
+            if (
+              !disableDefaultPropsExceptForClasses &&
+              config[propName] === undefined &&
+              defaultProps !== undefined
+            ) {
               // Resolve default props
               props[propName] = defaultProps[propName];
             } else {
@@ -2765,55 +2777,35 @@ if (__DEV__) {
         _init: lazyInitializer
       };
 
-      {
-        // In production, this would just set it on the object.
-        var defaultProps;
-        var propTypes; // $FlowFixMe[prop-missing]
+      if (!disableDefaultPropsExceptForClasses) {
+        {
+          // In production, this would just set it on the object.
+          var defaultProps; // $FlowFixMe[prop-missing]
 
-        Object.defineProperties(lazyType, {
-          defaultProps: {
-            configurable: true,
-            get: function () {
-              return defaultProps;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newDefaultProps) {
-              error(
-                "It is not supported to assign `defaultProps` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
+          Object.defineProperties(lazyType, {
+            defaultProps: {
+              configurable: true,
+              get: function () {
+                return defaultProps;
+              },
+              // $FlowFixMe[missing-local-annot]
+              set: function (newDefaultProps) {
+                error(
+                  "It is not supported to assign `defaultProps` to " +
+                    "a lazy component import. Either specify them where the component " +
+                    "is defined, or create a wrapping component around it."
+                );
 
-              defaultProps = newDefaultProps; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+                defaultProps = newDefaultProps; // Match production behavior more closely:
+                // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "defaultProps", {
-                enumerable: true
-              });
+                Object.defineProperty(lazyType, "defaultProps", {
+                  enumerable: true
+                });
+              }
             }
-          },
-          propTypes: {
-            configurable: true,
-            get: function () {
-              return propTypes;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newPropTypes) {
-              error(
-                "It is not supported to assign `propTypes` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
-
-              propTypes = newPropTypes; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
-
-              Object.defineProperty(lazyType, "propTypes", {
-                enumerable: true
-              });
-            }
-          }
-        });
+          });
+        }
       }
 
       return lazyType;
diff --git a/compiled/facebook-www/React-dev.modern.js b/compiled/facebook-www/React-dev.modern.js
index fbbd44a46a..e81bca2033 100644
--- a/compiled/facebook-www/React-dev.modern.js
+++ b/compiled/facebook-www/React-dev.modern.js
@@ -24,7 +24,7 @@ if (__DEV__) {
     ) {
       __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error());
     }
-    var ReactVersion = "19.0.0-www-modern-3e52800d";
+    var ReactVersion = "19.0.0-www-modern-3a8173ed";
 
     // ATTENTION
     // When adding new symbols to this file,
@@ -475,8 +475,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
     var disableLegacyMode = true;
 
     function getWrappedName(outerType, innerType, wrapperName) {
@@ -1639,14 +1640,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
@@ -1906,7 +1910,11 @@ if (__DEV__) {
 
         var defaultProps;
 
-        if (element.type && element.type.defaultProps) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          element.type &&
+          element.type.defaultProps
+        ) {
           defaultProps = element.type.defaultProps;
         }
 
@@ -1926,7 +1934,11 @@ if (__DEV__) {
             // backwards compatibility.
             !(enableRefAsProp && propName === "ref" && config.ref === undefined)
           ) {
-            if (config[propName] === undefined && defaultProps !== undefined) {
+            if (
+              !disableDefaultPropsExceptForClasses &&
+              config[propName] === undefined &&
+              defaultProps !== undefined
+            ) {
               // Resolve default props
               props[propName] = defaultProps[propName];
             } else {
@@ -2765,55 +2777,35 @@ if (__DEV__) {
         _init: lazyInitializer
       };
 
-      {
-        // In production, this would just set it on the object.
-        var defaultProps;
-        var propTypes; // $FlowFixMe[prop-missing]
+      if (!disableDefaultPropsExceptForClasses) {
+        {
+          // In production, this would just set it on the object.
+          var defaultProps; // $FlowFixMe[prop-missing]
 
-        Object.defineProperties(lazyType, {
-          defaultProps: {
-            configurable: true,
-            get: function () {
-              return defaultProps;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newDefaultProps) {
-              error(
-                "It is not supported to assign `defaultProps` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
+          Object.defineProperties(lazyType, {
+            defaultProps: {
+              configurable: true,
+              get: function () {
+                return defaultProps;
+              },
+              // $FlowFixMe[missing-local-annot]
+              set: function (newDefaultProps) {
+                error(
+                  "It is not supported to assign `defaultProps` to " +
+                    "a lazy component import. Either specify them where the component " +
+                    "is defined, or create a wrapping component around it."
+                );
 
-              defaultProps = newDefaultProps; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+                defaultProps = newDefaultProps; // Match production behavior more closely:
+                // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "defaultProps", {
-                enumerable: true
-              });
+                Object.defineProperty(lazyType, "defaultProps", {
+                  enumerable: true
+                });
+              }
             }
-          },
-          propTypes: {
-            configurable: true,
-            get: function () {
-              return propTypes;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newPropTypes) {
-              error(
-                "It is not supported to assign `propTypes` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
-
-              propTypes = newPropTypes; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
-
-              Object.defineProperty(lazyType, "propTypes", {
-                enumerable: true
-              });
-            }
-          }
-        });
+          });
+        }
       }
 
       return lazyType;
diff --git a/compiled/facebook-www/React-prod.classic.js b/compiled/facebook-www/React-prod.classic.js
index 313635748a..1321fa9560 100644
--- a/compiled/facebook-www/React-prod.classic.js
+++ b/compiled/facebook-www/React-prod.classic.js
@@ -85,6 +85,8 @@ var isArrayImpl = Array.isArray,
   enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   ReactCurrentDispatcher = { current: null },
   ReactCurrentCache = { current: null },
   ReactCurrentBatchConfig = { transition: null },
@@ -121,7 +123,7 @@ function jsxProd(type, config, maybeKey) {
       "key" !== propName &&
       (enableRefAsProp || "ref" !== propName) &&
       (props[propName] = config[propName]);
-  if (type && type.defaultProps)
+  if (!disableDefaultPropsExceptForClasses && type && type.defaultProps)
     for (propName in ((config = type.defaultProps), config))
       void 0 === props[propName] && (props[propName] = config[propName]);
   return ReactElement(
@@ -429,7 +431,11 @@ exports.cloneElement = function (element, config, children) {
       (enableRefAsProp || (ref = config.ref),
       (owner = ReactCurrentOwner.current));
     void 0 !== config.key && (key = "" + config.key);
-    if (element.type && element.type.defaultProps)
+    if (
+      !disableDefaultPropsExceptForClasses &&
+      element.type &&
+      element.type.defaultProps
+    )
       var defaultProps = element.type.defaultProps;
     for (propName in config)
       !hasOwnProperty.call(config, propName) ||
@@ -439,9 +445,11 @@ exports.cloneElement = function (element, config, children) {
         "__source" === propName ||
         (enableRefAsProp && "ref" === propName && void 0 === config.ref) ||
         (props[propName] =
-          void 0 === config[propName] && void 0 !== defaultProps
-            ? defaultProps[propName]
-            : config[propName]);
+          disableDefaultPropsExceptForClasses ||
+          void 0 !== config[propName] ||
+          void 0 === defaultProps
+            ? config[propName]
+            : defaultProps[propName]);
   }
   var propName = arguments.length - 2;
   if (1 === propName) props.children = children;
@@ -644,4 +652,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "19.0.0-www-classic-1ba025a1";
+exports.version = "19.0.0-www-classic-6f7d270a";
diff --git a/compiled/facebook-www/React-prod.modern.js b/compiled/facebook-www/React-prod.modern.js
index 4a6a84496d..992e6e6900 100644
--- a/compiled/facebook-www/React-prod.modern.js
+++ b/compiled/facebook-www/React-prod.modern.js
@@ -85,6 +85,8 @@ var isArrayImpl = Array.isArray,
   enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   ReactCurrentDispatcher = { current: null },
   ReactCurrentCache = { current: null },
   ReactCurrentBatchConfig = { transition: null },
@@ -121,7 +123,7 @@ function jsxProd(type, config, maybeKey) {
       "key" !== propName &&
       (enableRefAsProp || "ref" !== propName) &&
       (props[propName] = config[propName]);
-  if (type && type.defaultProps)
+  if (!disableDefaultPropsExceptForClasses && type && type.defaultProps)
     for (propName in ((config = type.defaultProps), config))
       void 0 === props[propName] && (props[propName] = config[propName]);
   return ReactElement(
@@ -429,7 +431,11 @@ exports.cloneElement = function (element, config, children) {
       (enableRefAsProp || (ref = config.ref),
       (owner = ReactCurrentOwner.current));
     void 0 !== config.key && (key = "" + config.key);
-    if (element.type && element.type.defaultProps)
+    if (
+      !disableDefaultPropsExceptForClasses &&
+      element.type &&
+      element.type.defaultProps
+    )
       var defaultProps = element.type.defaultProps;
     for (propName in config)
       !hasOwnProperty.call(config, propName) ||
@@ -439,9 +445,11 @@ exports.cloneElement = function (element, config, children) {
         "__source" === propName ||
         (enableRefAsProp && "ref" === propName && void 0 === config.ref) ||
         (props[propName] =
-          void 0 === config[propName] && void 0 !== defaultProps
-            ? defaultProps[propName]
-            : config[propName]);
+          disableDefaultPropsExceptForClasses ||
+          void 0 !== config[propName] ||
+          void 0 === defaultProps
+            ? config[propName]
+            : defaultProps[propName]);
   }
   var propName = arguments.length - 2;
   if (1 === propName) props.children = children;
@@ -644,4 +652,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "19.0.0-www-modern-1ba025a1";
+exports.version = "19.0.0-www-modern-6f7d270a";
diff --git a/compiled/facebook-www/React-profiling.classic.js b/compiled/facebook-www/React-profiling.classic.js
index 08b76e2c05..45d8fb65fe 100644
--- a/compiled/facebook-www/React-profiling.classic.js
+++ b/compiled/facebook-www/React-profiling.classic.js
@@ -89,6 +89,8 @@ var isArrayImpl = Array.isArray,
   enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   ReactCurrentDispatcher = { current: null },
   ReactCurrentCache = { current: null },
   ReactCurrentBatchConfig = { transition: null },
@@ -125,7 +127,7 @@ function jsxProd(type, config, maybeKey) {
       "key" !== propName &&
       (enableRefAsProp || "ref" !== propName) &&
       (props[propName] = config[propName]);
-  if (type && type.defaultProps)
+  if (!disableDefaultPropsExceptForClasses && type && type.defaultProps)
     for (propName in ((config = type.defaultProps), config))
       void 0 === props[propName] && (props[propName] = config[propName]);
   return ReactElement(
@@ -433,7 +435,11 @@ exports.cloneElement = function (element, config, children) {
       (enableRefAsProp || (ref = config.ref),
       (owner = ReactCurrentOwner.current));
     void 0 !== config.key && (key = "" + config.key);
-    if (element.type && element.type.defaultProps)
+    if (
+      !disableDefaultPropsExceptForClasses &&
+      element.type &&
+      element.type.defaultProps
+    )
       var defaultProps = element.type.defaultProps;
     for (propName in config)
       !hasOwnProperty.call(config, propName) ||
@@ -443,9 +449,11 @@ exports.cloneElement = function (element, config, children) {
         "__source" === propName ||
         (enableRefAsProp && "ref" === propName && void 0 === config.ref) ||
         (props[propName] =
-          void 0 === config[propName] && void 0 !== defaultProps
-            ? defaultProps[propName]
-            : config[propName]);
+          disableDefaultPropsExceptForClasses ||
+          void 0 !== config[propName] ||
+          void 0 === defaultProps
+            ? config[propName]
+            : defaultProps[propName]);
   }
   var propName = arguments.length - 2;
   if (1 === propName) props.children = children;
@@ -648,7 +656,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "19.0.0-www-classic-fc935265";
+exports.version = "19.0.0-www-classic-26c19df2";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&
diff --git a/compiled/facebook-www/React-profiling.modern.js b/compiled/facebook-www/React-profiling.modern.js
index f733a6bd50..4ef4a951e7 100644
--- a/compiled/facebook-www/React-profiling.modern.js
+++ b/compiled/facebook-www/React-profiling.modern.js
@@ -89,6 +89,8 @@ var isArrayImpl = Array.isArray,
   enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   ReactCurrentDispatcher = { current: null },
   ReactCurrentCache = { current: null },
   ReactCurrentBatchConfig = { transition: null },
@@ -125,7 +127,7 @@ function jsxProd(type, config, maybeKey) {
       "key" !== propName &&
       (enableRefAsProp || "ref" !== propName) &&
       (props[propName] = config[propName]);
-  if (type && type.defaultProps)
+  if (!disableDefaultPropsExceptForClasses && type && type.defaultProps)
     for (propName in ((config = type.defaultProps), config))
       void 0 === props[propName] && (props[propName] = config[propName]);
   return ReactElement(
@@ -433,7 +435,11 @@ exports.cloneElement = function (element, config, children) {
       (enableRefAsProp || (ref = config.ref),
       (owner = ReactCurrentOwner.current));
     void 0 !== config.key && (key = "" + config.key);
-    if (element.type && element.type.defaultProps)
+    if (
+      !disableDefaultPropsExceptForClasses &&
+      element.type &&
+      element.type.defaultProps
+    )
       var defaultProps = element.type.defaultProps;
     for (propName in config)
       !hasOwnProperty.call(config, propName) ||
@@ -443,9 +449,11 @@ exports.cloneElement = function (element, config, children) {
         "__source" === propName ||
         (enableRefAsProp && "ref" === propName && void 0 === config.ref) ||
         (props[propName] =
-          void 0 === config[propName] && void 0 !== defaultProps
-            ? defaultProps[propName]
-            : config[propName]);
+          disableDefaultPropsExceptForClasses ||
+          void 0 !== config[propName] ||
+          void 0 === defaultProps
+            ? config[propName]
+            : defaultProps[propName]);
   }
   var propName = arguments.length - 2;
   if (1 === propName) props.children = children;
@@ -648,7 +656,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "19.0.0-www-modern-fc935265";
+exports.version = "19.0.0-www-modern-26c19df2";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&
diff --git a/compiled/facebook-www/ReactART-dev.classic.js b/compiled/facebook-www/ReactART-dev.classic.js
index 362c3ffc83..e2a97177ee 100644
--- a/compiled/facebook-www/ReactART-dev.classic.js
+++ b/compiled/facebook-www/ReactART-dev.classic.js
@@ -66,7 +66,7 @@ if (__DEV__) {
       return self;
     }
 
-    var ReactVersion = "19.0.0-www-classic-086110c8";
+    var ReactVersion = "19.0.0-www-classic-e11823db";
 
     var LegacyRoot = 0;
     var ConcurrentRoot = 1;
@@ -185,8 +185,9 @@ if (__DEV__) {
       enableInfiniteRenderLoopDetection =
         dynamicFeatureFlags.enableInfiniteRenderLoopDetection,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -14497,7 +14498,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -14521,10 +14526,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -15550,7 +15558,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -15576,18 +15585,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -16663,7 +16675,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -16685,7 +16699,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -16702,14 +16718,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -16808,7 +16831,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -18724,9 +18750,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -18783,9 +18813,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -18815,9 +18846,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -27653,9 +27691,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           {
@@ -27687,9 +27729,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
diff --git a/compiled/facebook-www/ReactART-dev.modern.js b/compiled/facebook-www/ReactART-dev.modern.js
index 474b60b528..231de1c158 100644
--- a/compiled/facebook-www/ReactART-dev.modern.js
+++ b/compiled/facebook-www/ReactART-dev.modern.js
@@ -66,7 +66,7 @@ if (__DEV__) {
       return self;
     }
 
-    var ReactVersion = "19.0.0-www-modern-792ee5bd";
+    var ReactVersion = "19.0.0-www-modern-ab20b5da";
 
     var LegacyRoot = 0;
     var ConcurrentRoot = 1;
@@ -185,8 +185,9 @@ if (__DEV__) {
       enableInfiniteRenderLoopDetection =
         dynamicFeatureFlags.enableInfiniteRenderLoopDetection,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -14207,7 +14208,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -14231,10 +14236,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -15164,7 +15172,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -15190,18 +15199,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -16215,7 +16227,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -16237,7 +16251,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -16254,14 +16270,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -16324,7 +16347,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -18150,9 +18176,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -18209,9 +18239,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -18241,9 +18272,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -26860,9 +26898,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           next = replayFunctionComponent(
@@ -26885,9 +26927,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
diff --git a/compiled/facebook-www/ReactART-prod.classic.js b/compiled/facebook-www/ReactART-prod.classic.js
index 660322869e..13dbf26912 100644
--- a/compiled/facebook-www/ReactART-prod.classic.js
+++ b/compiled/facebook-www/ReactART-prod.classic.js
@@ -84,6 +84,8 @@ var ReactSharedInternals =
     dynamicFeatureFlags.enableInfiniteRenderLoopDetection,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -3962,7 +3964,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -3974,7 +3979,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -4433,7 +4439,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -5638,7 +5644,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -5653,7 +5661,9 @@ function beginWork(current, workInProgress, renderLanes) {
               ((elementType = current.$$typeof),
               elementType === REACT_FORWARD_REF_TYPE)
             ) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -5664,13 +5674,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (elementType === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -5684,9 +5698,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -5801,9 +5816,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateForwardRef(
           current,
           workInProgress,
@@ -5890,8 +5906,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (elementType = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (elementType = resolveDefaultProps(props.type, elementType)),
+        (elementType = workInProgress.pendingProps),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props, elementType)),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props.type, elementType)),
         updateMemoComponent(
           current,
           workInProgress,
@@ -9672,9 +9693,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       var context = isContextProvider(Component)
         ? previousContext
         : contextStackCursor$1.current;
@@ -9692,9 +9714,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -10673,7 +10696,7 @@ var slice = Array.prototype.slice,
       return null;
     },
     bundleType: 0,
-    version: "19.0.0-www-classic-55d59959",
+    version: "19.0.0-www-classic-442df77a",
     rendererPackageName: "react-art"
   };
 var internals$jscomp$inline_1317 = {
@@ -10704,7 +10727,7 @@ var internals$jscomp$inline_1317 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-classic-55d59959"
+  reconcilerVersion: "19.0.0-www-classic-442df77a"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1318 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
diff --git a/compiled/facebook-www/ReactART-prod.modern.js b/compiled/facebook-www/ReactART-prod.modern.js
index dbbb82279f..ffe1fd3530 100644
--- a/compiled/facebook-www/ReactART-prod.modern.js
+++ b/compiled/facebook-www/ReactART-prod.modern.js
@@ -84,6 +84,8 @@ var ReactSharedInternals =
     dynamicFeatureFlags.enableInfiniteRenderLoopDetection,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -3698,7 +3700,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -3710,7 +3715,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -4129,7 +4135,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -5302,7 +5308,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -5314,7 +5322,9 @@ function beginWork(current, workInProgress, renderLanes) {
         else {
           if (void 0 !== current && null !== current)
             if (((init = current.$$typeof), init === REACT_FORWARD_REF_TYPE)) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -5325,13 +5335,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (init === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -5345,9 +5359,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -5456,9 +5471,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateForwardRef(current, workInProgress, props, init, renderLanes)
       );
     case 7:
@@ -5531,8 +5547,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (init = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (init = resolveDefaultProps(props.type, init)),
+        (init = workInProgress.pendingProps),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props, init)),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props.type, init)),
         updateMemoComponent(current, workInProgress, props, init, renderLanes)
       );
     case 15:
@@ -9195,9 +9216,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -9211,9 +9233,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -10145,7 +10168,7 @@ var slice = Array.prototype.slice,
       return null;
     },
     bundleType: 0,
-    version: "19.0.0-www-modern-c8d23bec",
+    version: "19.0.0-www-modern-292e1686",
     rendererPackageName: "react-art"
   };
 var internals$jscomp$inline_1298 = {
@@ -10176,7 +10199,7 @@ var internals$jscomp$inline_1298 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-modern-c8d23bec"
+  reconcilerVersion: "19.0.0-www-modern-292e1686"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1299 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
diff --git a/compiled/facebook-www/ReactDOM-dev.classic.js b/compiled/facebook-www/ReactDOM-dev.classic.js
index 0ed1a3295d..2da877e887 100644
--- a/compiled/facebook-www/ReactDOM-dev.classic.js
+++ b/compiled/facebook-www/ReactDOM-dev.classic.js
@@ -149,7 +149,9 @@ if (__DEV__) {
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
       enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
       favorSafetyOverHydrationPerf =
-        dynamicFeatureFlags.favorSafetyOverHydrationPerf; // On WWW, false is used for a new modern build.
+        dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -19148,7 +19150,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -19172,10 +19178,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -20337,7 +20346,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -20363,18 +20373,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -21604,7 +21617,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -21626,7 +21641,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -21643,14 +21660,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -21749,7 +21773,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -23753,9 +23780,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -23816,9 +23847,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -23848,9 +23880,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -33300,9 +33339,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           {
@@ -33334,9 +33377,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -36213,7 +36260,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-classic-cd5ebeba";
+    var ReactVersion = "19.0.0-www-classic-82184e0e";
 
     function createPortal$1(
       children,
diff --git a/compiled/facebook-www/ReactDOM-dev.modern.js b/compiled/facebook-www/ReactDOM-dev.modern.js
index ebe081f39b..e2aca2db89 100644
--- a/compiled/facebook-www/ReactDOM-dev.modern.js
+++ b/compiled/facebook-www/ReactDOM-dev.modern.js
@@ -164,7 +164,9 @@ if (__DEV__) {
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
       enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
       favorSafetyOverHydrationPerf =
-        dynamicFeatureFlags.favorSafetyOverHydrationPerf; // On WWW, true is used for a new modern build.
+        dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -29308,7 +29310,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -29332,10 +29338,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -30362,7 +30371,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -30388,18 +30398,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -31567,7 +31580,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -31589,7 +31604,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -31606,14 +31623,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -31676,7 +31700,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -33590,9 +33617,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -33653,9 +33684,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -33685,9 +33717,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -42902,9 +42941,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           next = replayFunctionComponent(
@@ -42927,9 +42970,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -45707,7 +45754,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-modern-b12aa191";
+    var ReactVersion = "19.0.0-www-modern-bedb0a17";
 
     function createPortal$1(
       children,
diff --git a/compiled/facebook-www/ReactDOM-prod.classic.js b/compiled/facebook-www/ReactDOM-prod.classic.js
index 91d4449cd8..1ab5ec53f5 100644
--- a/compiled/facebook-www/ReactDOM-prod.classic.js
+++ b/compiled/facebook-www/ReactDOM-prod.classic.js
@@ -62,6 +62,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -4803,7 +4805,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -4815,7 +4820,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -5347,7 +5353,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -6656,7 +6662,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -6671,7 +6679,9 @@ function beginWork(current, workInProgress, renderLanes) {
               ((elementType = current.$$typeof),
               elementType === REACT_FORWARD_REF_TYPE)
             ) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -6682,13 +6692,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (elementType === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -6702,9 +6716,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -6956,9 +6971,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateForwardRef(
           current,
           workInProgress,
@@ -7045,8 +7061,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (elementType = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (elementType = resolveDefaultProps(props.type, elementType)),
+        (elementType = workInProgress.pendingProps),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props, elementType)),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props.type, elementType)),
         updateMemoComponent(
           current,
           workInProgress,
@@ -11502,9 +11523,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       var context = isContextProvider(Component)
         ? previousContext
         : contextStackCursor.current;
@@ -11522,9 +11544,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -16993,7 +17016,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1704 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-classic-83138ece",
+  version: "19.0.0-www-classic-6a77288c",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2134 = {
@@ -17023,7 +17046,7 @@ var internals$jscomp$inline_2134 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-classic-83138ece"
+  reconcilerVersion: "19.0.0-www-classic-6a77288c"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2135 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -17479,4 +17502,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-classic-83138ece";
+exports.version = "19.0.0-www-classic-6a77288c";
diff --git a/compiled/facebook-www/ReactDOM-prod.modern.js b/compiled/facebook-www/ReactDOM-prod.modern.js
index d4a4a83d51..b5aa706558 100644
--- a/compiled/facebook-www/ReactDOM-prod.modern.js
+++ b/compiled/facebook-www/ReactDOM-prod.modern.js
@@ -78,6 +78,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -8356,7 +8358,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -8368,7 +8373,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -8803,7 +8809,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -10073,7 +10079,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -10085,7 +10093,9 @@ function beginWork(current, workInProgress, renderLanes) {
         else {
           if (void 0 !== current && null !== current)
             if (((init = current.$$typeof), init === REACT_FORWARD_REF_TYPE)) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -10096,13 +10106,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (init === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -10116,9 +10130,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -10367,9 +10382,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateForwardRef(current, workInProgress, props, init, renderLanes)
       );
     case 7:
@@ -10442,8 +10458,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (init = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (init = resolveDefaultProps(props.type, init)),
+        (init = workInProgress.pendingProps),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props, init)),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props.type, init)),
         updateMemoComponent(current, workInProgress, props, init, renderLanes)
       );
     case 15:
@@ -14786,9 +14807,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -14802,9 +14824,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -16368,7 +16391,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1687 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-modern-8cca1f01",
+  version: "19.0.0-www-modern-182c8cda",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2114 = {
@@ -16398,7 +16421,7 @@ var internals$jscomp$inline_2114 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-modern-8cca1f01"
+  reconcilerVersion: "19.0.0-www-modern-182c8cda"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2115 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -16701,4 +16724,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-modern-8cca1f01";
+exports.version = "19.0.0-www-modern-182c8cda";
diff --git a/compiled/facebook-www/ReactDOM-profiling.classic.js b/compiled/facebook-www/ReactDOM-profiling.classic.js
index 93ebac46cc..26b40e0491 100644
--- a/compiled/facebook-www/ReactDOM-profiling.classic.js
+++ b/compiled/facebook-www/ReactDOM-profiling.classic.js
@@ -66,6 +66,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   enableSchedulingProfiler = dynamicFeatureFlags.enableSchedulingProfiler,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
@@ -5011,7 +5013,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -5023,7 +5028,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -5558,7 +5564,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -6898,7 +6904,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -6913,7 +6921,9 @@ function beginWork(current, workInProgress, renderLanes) {
               ((elementType = current.$$typeof),
               elementType === REACT_FORWARD_REF_TYPE)
             ) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -6924,13 +6934,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (elementType === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -6944,9 +6958,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -7198,9 +7213,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateForwardRef(
           current,
           workInProgress,
@@ -7293,8 +7309,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (elementType = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (elementType = resolveDefaultProps(props.type, elementType)),
+        (elementType = workInProgress.pendingProps),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props, elementType)),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props.type, elementType)),
         updateMemoComponent(
           current,
           workInProgress,
@@ -12165,9 +12186,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       var context = isContextProvider(Component)
         ? previousContext
         : contextStackCursor.current;
@@ -12185,9 +12207,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -17741,7 +17764,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1790 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-classic-1231a9cb",
+  version: "19.0.0-www-classic-1006227c",
   rendererPackageName: "react-dom"
 };
 (function (internals) {
@@ -17785,7 +17808,7 @@ var devToolsConfig$jscomp$inline_1790 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-classic-1231a9cb"
+  reconcilerVersion: "19.0.0-www-classic-1006227c"
 });
 var ReactFiberErrorDialogWWW = require("ReactFiberErrorDialog");
 if ("function" !== typeof ReactFiberErrorDialogWWW.showErrorDialog)
@@ -18228,7 +18251,7 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-classic-1231a9cb";
+exports.version = "19.0.0-www-classic-1006227c";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&
diff --git a/compiled/facebook-www/ReactDOM-profiling.modern.js b/compiled/facebook-www/ReactDOM-profiling.modern.js
index 889e9acadc..b5b56a7a11 100644
--- a/compiled/facebook-www/ReactDOM-profiling.modern.js
+++ b/compiled/facebook-www/ReactDOM-profiling.modern.js
@@ -82,6 +82,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   enableSchedulingProfiler = dynamicFeatureFlags.enableSchedulingProfiler,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
@@ -8564,7 +8566,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -8576,7 +8581,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -9014,7 +9020,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -10298,7 +10304,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -10310,7 +10318,9 @@ function beginWork(current, workInProgress, renderLanes) {
         else {
           if (void 0 !== current && null !== current)
             if (((init = current.$$typeof), init === REACT_FORWARD_REF_TYPE)) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -10321,13 +10331,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (init === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -10341,9 +10355,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -10592,9 +10607,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateForwardRef(current, workInProgress, props, init, renderLanes)
       );
     case 7:
@@ -10673,8 +10689,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (init = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (init = resolveDefaultProps(props.type, init)),
+        (init = workInProgress.pendingProps),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props, init)),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props.type, init)),
         updateMemoComponent(current, workInProgress, props, init, renderLanes)
       );
     case 15:
@@ -15432,9 +15453,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -15448,9 +15470,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -17099,7 +17122,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1773 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-modern-31fa3d44",
+  version: "19.0.0-www-modern-89fa1e2e",
   rendererPackageName: "react-dom"
 };
 (function (internals) {
@@ -17143,7 +17166,7 @@ var devToolsConfig$jscomp$inline_1773 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-modern-31fa3d44"
+  reconcilerVersion: "19.0.0-www-modern-89fa1e2e"
 });
 var ReactFiberErrorDialogWWW = require("ReactFiberErrorDialog");
 if ("function" !== typeof ReactFiberErrorDialogWWW.showErrorDialog)
@@ -17433,7 +17456,7 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-modern-31fa3d44";
+exports.version = "19.0.0-www-modern-89fa1e2e";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&
diff --git a/compiled/facebook-www/ReactDOMServer-dev.classic.js b/compiled/facebook-www/ReactDOMServer-dev.classic.js
index 1173987eeb..4405b38f0c 100644
--- a/compiled/facebook-www/ReactDOMServer-dev.classic.js
+++ b/compiled/facebook-www/ReactDOMServer-dev.classic.js
@@ -19,7 +19,7 @@ if (__DEV__) {
     var React = require("react");
     var ReactDOM = require("react-dom");
 
-    var ReactVersion = "19.0.0-www-classic-6ac6cbda";
+    var ReactVersion = "19.0.0-www-classic-de6e54b3";
 
     // This refers to a WWW module.
     var warningWWW = require("warning");
@@ -678,8 +678,9 @@ if (__DEV__) {
       enableUseDeferredValueInitialArg =
         dynamicFeatureFlags.enableUseDeferredValueInitialArg,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
 
     // $FlowFixMe[method-unbinding]
     var hasOwnProperty = Object.prototype.hasOwnProperty;
@@ -11997,12 +11998,27 @@ if (__DEV__) {
     }
 
     function resolveClassComponentProps(Component, baseProps) {
-      var newProps = baseProps; // TODO: This is where defaultProps should be resolved, too.
+      var newProps = baseProps; // Resolve default props. Taken from old JSX runtime, where this used to live.
+
+      var defaultProps = Component.defaultProps;
+
+      if (defaultProps && disableDefaultPropsExceptForClasses) {
+        newProps = assign({}, newProps, baseProps);
+
+        for (var propName in defaultProps) {
+          if (newProps[propName] === undefined) {
+            newProps[propName] = defaultProps[propName];
+          }
+        }
+      }
 
       if (enableRefAsProp) {
         // Remove ref from the props object, if it exists.
         if ("ref" in newProps) {
-          newProps = assign({}, newProps);
+          if (newProps === baseProps) {
+            newProps = assign({}, newProps);
+          }
+
           delete newProps.ref;
         }
       }
@@ -12177,7 +12193,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
@@ -12224,7 +12243,13 @@ if (__DEV__) {
       }
     }
 
-    function resolveDefaultProps(Component, baseProps) {
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -12290,7 +12315,10 @@ if (__DEV__) {
 
     function renderMemo(request, task, keyPath, type, props, ref) {
       var innerType = type.type;
-      var resolvedProps = resolveDefaultProps(innerType, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        innerType,
+        props
+      );
       renderElement(request, task, keyPath, innerType, resolvedProps, ref);
     }
 
@@ -12354,7 +12382,10 @@ if (__DEV__) {
       var payload = lazyComponent._payload;
       var init = lazyComponent._init;
       var Component = init(payload);
-      var resolvedProps = resolveDefaultProps(Component, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        Component,
+        props
+      );
       renderElement(request, task, keyPath, Component, resolvedProps, ref);
       task.componentStack = previousComponentStack;
     }
diff --git a/compiled/facebook-www/ReactDOMServer-dev.modern.js b/compiled/facebook-www/ReactDOMServer-dev.modern.js
index 4976e7a54c..1423248457 100644
--- a/compiled/facebook-www/ReactDOMServer-dev.modern.js
+++ b/compiled/facebook-www/ReactDOMServer-dev.modern.js
@@ -19,7 +19,7 @@ if (__DEV__) {
     var React = require("react");
     var ReactDOM = require("react-dom");
 
-    var ReactVersion = "19.0.0-www-modern-53247bf3";
+    var ReactVersion = "19.0.0-www-modern-5712afa3";
 
     // This refers to a WWW module.
     var warningWWW = require("warning");
@@ -678,8 +678,9 @@ if (__DEV__) {
       enableUseDeferredValueInitialArg =
         dynamicFeatureFlags.enableUseDeferredValueInitialArg,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
 
     // $FlowFixMe[method-unbinding]
     var hasOwnProperty = Object.prototype.hasOwnProperty;
@@ -11900,12 +11901,27 @@ if (__DEV__) {
     }
 
     function resolveClassComponentProps(Component, baseProps) {
-      var newProps = baseProps; // TODO: This is where defaultProps should be resolved, too.
+      var newProps = baseProps; // Resolve default props. Taken from old JSX runtime, where this used to live.
+
+      var defaultProps = Component.defaultProps;
+
+      if (defaultProps && disableDefaultPropsExceptForClasses) {
+        newProps = assign({}, newProps, baseProps);
+
+        for (var propName in defaultProps) {
+          if (newProps[propName] === undefined) {
+            newProps[propName] = defaultProps[propName];
+          }
+        }
+      }
 
       if (enableRefAsProp) {
         // Remove ref from the props object, if it exists.
         if ("ref" in newProps) {
-          newProps = assign({}, newProps);
+          if (newProps === baseProps) {
+            newProps = assign({}, newProps);
+          }
+
           delete newProps.ref;
         }
       }
@@ -12082,7 +12098,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
@@ -12129,7 +12148,13 @@ if (__DEV__) {
       }
     }
 
-    function resolveDefaultProps(Component, baseProps) {
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -12195,7 +12220,10 @@ if (__DEV__) {
 
     function renderMemo(request, task, keyPath, type, props, ref) {
       var innerType = type.type;
-      var resolvedProps = resolveDefaultProps(innerType, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        innerType,
+        props
+      );
       renderElement(request, task, keyPath, innerType, resolvedProps, ref);
     }
 
@@ -12259,7 +12287,10 @@ if (__DEV__) {
       var payload = lazyComponent._payload;
       var init = lazyComponent._init;
       var Component = init(payload);
-      var resolvedProps = resolveDefaultProps(Component, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        Component,
+        props
+      );
       renderElement(request, task, keyPath, Component, resolvedProps, ref);
       task.componentStack = previousComponentStack;
     }
diff --git a/compiled/facebook-www/ReactDOMServer-prod.classic.js b/compiled/facebook-www/ReactDOMServer-prod.classic.js
index 07d531b8de..bd100bb541 100644
--- a/compiled/facebook-www/ReactDOMServer-prod.classic.js
+++ b/compiled/facebook-www/ReactDOMServer-prod.classic.js
@@ -133,6 +133,8 @@ var assign = Object.assign,
     dynamicFeatureFlags.enableUseDeferredValueInitialArg,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   hasOwnProperty = Object.prototype.hasOwnProperty,
   VALID_ATTRIBUTE_NAME_REGEX = RegExp(
     "^[:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD][:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD\\-.0-9\\u00B7\\u0300-\\u036F\\u203F-\\u2040]*$"
@@ -2617,16 +2619,16 @@ function createRenderState(resumableState, generateStaticMarkup) {
       "\x3c/script>"
     );
   bootstrapScriptContent = idPrefix + "P:";
-  var JSCompiler_object_inline_segmentPrefix_1629 = idPrefix + "S:";
+  var JSCompiler_object_inline_segmentPrefix_1631 = idPrefix + "S:";
   idPrefix += "B:";
-  var JSCompiler_object_inline_preconnects_1643 = new Set(),
-    JSCompiler_object_inline_fontPreloads_1644 = new Set(),
-    JSCompiler_object_inline_highImagePreloads_1645 = new Set(),
-    JSCompiler_object_inline_styles_1646 = new Map(),
-    JSCompiler_object_inline_bootstrapScripts_1647 = new Set(),
-    JSCompiler_object_inline_scripts_1648 = new Set(),
-    JSCompiler_object_inline_bulkPreloads_1649 = new Set(),
-    JSCompiler_object_inline_preloads_1650 = {
+  var JSCompiler_object_inline_preconnects_1645 = new Set(),
+    JSCompiler_object_inline_fontPreloads_1646 = new Set(),
+    JSCompiler_object_inline_highImagePreloads_1647 = new Set(),
+    JSCompiler_object_inline_styles_1648 = new Map(),
+    JSCompiler_object_inline_bootstrapScripts_1649 = new Set(),
+    JSCompiler_object_inline_scripts_1650 = new Set(),
+    JSCompiler_object_inline_bulkPreloads_1651 = new Set(),
+    JSCompiler_object_inline_preloads_1652 = {
       images: new Map(),
       stylesheets: new Map(),
       scripts: new Map(),
@@ -2663,7 +2665,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
       scriptConfig.moduleScriptResources[href] = null;
       scriptConfig = [];
       pushLinkImpl(scriptConfig, props);
-      JSCompiler_object_inline_bootstrapScripts_1647.add(scriptConfig);
+      JSCompiler_object_inline_bootstrapScripts_1649.add(scriptConfig);
       bootstrapChunks.push('<script src="', escapeTextForBrowser(src));
       "string" === typeof integrity &&
         bootstrapChunks.push('" integrity="', escapeTextForBrowser(integrity));
@@ -2704,7 +2706,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
         (props.moduleScriptResources[scriptConfig] = null),
         (props = []),
         pushLinkImpl(props, integrity),
-        JSCompiler_object_inline_bootstrapScripts_1647.add(props),
+        JSCompiler_object_inline_bootstrapScripts_1649.add(props),
         bootstrapChunks.push(
           '<script type="module" src="',
           escapeTextForBrowser(i)
@@ -2719,7 +2721,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
         bootstrapChunks.push('" async="">\x3c/script>');
   return {
     placeholderPrefix: bootstrapScriptContent,
-    segmentPrefix: JSCompiler_object_inline_segmentPrefix_1629,
+    segmentPrefix: JSCompiler_object_inline_segmentPrefix_1631,
     boundaryPrefix: idPrefix,
     startInlineScript: "<script>",
     htmlChunks: null,
@@ -2739,14 +2741,14 @@ function createRenderState(resumableState, generateStaticMarkup) {
     charsetChunks: [],
     viewportChunks: [],
     hoistableChunks: [],
-    preconnects: JSCompiler_object_inline_preconnects_1643,
-    fontPreloads: JSCompiler_object_inline_fontPreloads_1644,
-    highImagePreloads: JSCompiler_object_inline_highImagePreloads_1645,
-    styles: JSCompiler_object_inline_styles_1646,
-    bootstrapScripts: JSCompiler_object_inline_bootstrapScripts_1647,
-    scripts: JSCompiler_object_inline_scripts_1648,
-    bulkPreloads: JSCompiler_object_inline_bulkPreloads_1649,
-    preloads: JSCompiler_object_inline_preloads_1650,
+    preconnects: JSCompiler_object_inline_preconnects_1645,
+    fontPreloads: JSCompiler_object_inline_fontPreloads_1646,
+    highImagePreloads: JSCompiler_object_inline_highImagePreloads_1647,
+    styles: JSCompiler_object_inline_styles_1648,
+    bootstrapScripts: JSCompiler_object_inline_bootstrapScripts_1649,
+    scripts: JSCompiler_object_inline_scripts_1650,
+    bulkPreloads: JSCompiler_object_inline_bulkPreloads_1651,
+    preloads: JSCompiler_object_inline_preloads_1652,
     stylesToHoist: !1,
     generateStaticMarkup: generateStaticMarkup
   };
@@ -3756,7 +3758,8 @@ function finishFunctionComponent(
     : renderNodeDestructive(request, task, children, -1);
   task.keyPath = actionStateCount;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -3802,32 +3805,40 @@ function renderContextProvider(request, task, keyPath, context, props) {
 function renderElement(request, task, keyPath, type, props, ref) {
   if ("function" === typeof type)
     if (type.prototype && type.prototype.isReactComponent) {
+      var JSCompiler_inline_result,
+        newProps = props;
+      if (
+        (JSCompiler_inline_result = type.defaultProps) &&
+        disableDefaultPropsExceptForClasses
+      ) {
+        newProps = assign({}, newProps, props);
+        for (var propName in JSCompiler_inline_result)
+          void 0 === newProps[propName] &&
+            (newProps[propName] = JSCompiler_inline_result[propName]);
+      }
       enableRefAsProp &&
-        "ref" in props &&
-        ((props = assign({}, props)), delete props.ref);
-      var JSCompiler_inline_result = props;
+        "ref" in newProps &&
+        (newProps === props && (newProps = assign({}, newProps)),
+        delete newProps.ref);
+      JSCompiler_inline_result = newProps;
       props = task.componentStack;
       task.componentStack = { tag: 2, parent: task.componentStack, type: type };
       ref = getMaskedContext(type, task.legacyContext);
-      var JSCompiler_inline_result$jscomp$0 = type.contextType;
-      JSCompiler_inline_result$jscomp$0 = new type(
+      newProps = type.contextType;
+      newProps = new type(
         JSCompiler_inline_result,
-        "object" === typeof JSCompiler_inline_result$jscomp$0 &&
-        null !== JSCompiler_inline_result$jscomp$0
-          ? JSCompiler_inline_result$jscomp$0._currentValue2
+        "object" === typeof newProps && null !== newProps
+          ? newProps._currentValue2
           : ref
       );
-      var initialState =
-        void 0 !== JSCompiler_inline_result$jscomp$0.state
-          ? JSCompiler_inline_result$jscomp$0.state
-          : null;
-      JSCompiler_inline_result$jscomp$0.updater = classComponentUpdater;
-      JSCompiler_inline_result$jscomp$0.props = JSCompiler_inline_result;
-      JSCompiler_inline_result$jscomp$0.state = initialState;
-      var internalInstance = { queue: [], replace: !1 };
-      JSCompiler_inline_result$jscomp$0._reactInternals = internalInstance;
+      var initialState = void 0 !== newProps.state ? newProps.state : null;
+      newProps.updater = classComponentUpdater;
+      newProps.props = JSCompiler_inline_result;
+      newProps.state = initialState;
+      propName = { queue: [], replace: !1 };
+      newProps._reactInternals = propName;
       var contextType = type.contextType;
-      JSCompiler_inline_result$jscomp$0.context =
+      newProps.context =
         "object" === typeof contextType && null !== contextType
           ? contextType._currentValue2
           : ref;
@@ -3838,42 +3849,35 @@ function renderElement(request, task, keyPath, type, props, ref) {
           null === contextType || void 0 === contextType
             ? initialState
             : assign({}, initialState, contextType)),
-        (JSCompiler_inline_result$jscomp$0.state = initialState));
+        (newProps.state = initialState));
       if (
         "function" !== typeof type.getDerivedStateFromProps &&
-        "function" !==
-          typeof JSCompiler_inline_result$jscomp$0.getSnapshotBeforeUpdate &&
-        ("function" ===
-          typeof JSCompiler_inline_result$jscomp$0.UNSAFE_componentWillMount ||
-          "function" ===
-            typeof JSCompiler_inline_result$jscomp$0.componentWillMount)
+        "function" !== typeof newProps.getSnapshotBeforeUpdate &&
+        ("function" === typeof newProps.UNSAFE_componentWillMount ||
+          "function" === typeof newProps.componentWillMount)
       )
         if (
-          ((initialState = JSCompiler_inline_result$jscomp$0.state),
-          "function" ===
-            typeof JSCompiler_inline_result$jscomp$0.componentWillMount &&
-            JSCompiler_inline_result$jscomp$0.componentWillMount(),
-          "function" ===
-            typeof JSCompiler_inline_result$jscomp$0.UNSAFE_componentWillMount &&
-            JSCompiler_inline_result$jscomp$0.UNSAFE_componentWillMount(),
-          initialState !== JSCompiler_inline_result$jscomp$0.state &&
+          ((initialState = newProps.state),
+          "function" === typeof newProps.componentWillMount &&
+            newProps.componentWillMount(),
+          "function" === typeof newProps.UNSAFE_componentWillMount &&
+            newProps.UNSAFE_componentWillMount(),
+          initialState !== newProps.state &&
             classComponentUpdater.enqueueReplaceState(
-              JSCompiler_inline_result$jscomp$0,
-              JSCompiler_inline_result$jscomp$0.state,
+              newProps,
+              newProps.state,
               null
             ),
-          null !== internalInstance.queue && 0 < internalInstance.queue.length)
+          null !== propName.queue && 0 < propName.queue.length)
         ) {
-          initialState = internalInstance.queue;
-          var oldReplace = internalInstance.replace;
-          internalInstance.queue = null;
-          internalInstance.replace = !1;
+          initialState = propName.queue;
+          var oldReplace = propName.replace;
+          propName.queue = null;
+          propName.replace = !1;
           if (oldReplace && 1 === initialState.length)
-            JSCompiler_inline_result$jscomp$0.state = initialState[0];
+            newProps.state = initialState[0];
           else {
-            internalInstance = oldReplace
-              ? initialState[0]
-              : JSCompiler_inline_result$jscomp$0.state;
+            propName = oldReplace ? initialState[0] : newProps.state;
             contextType = !0;
             for (
               oldReplace = oldReplace ? 1 : 0;
@@ -3884,8 +3888,8 @@ function renderElement(request, task, keyPath, type, props, ref) {
               partial =
                 "function" === typeof partial
                   ? partial.call(
-                      JSCompiler_inline_result$jscomp$0,
-                      internalInstance,
+                      newProps,
+                      propName,
                       JSCompiler_inline_result,
                       ref
                     )
@@ -3893,25 +3897,20 @@ function renderElement(request, task, keyPath, type, props, ref) {
               null != partial &&
                 (contextType
                   ? ((contextType = !1),
-                    (internalInstance = assign({}, internalInstance, partial)))
-                  : assign(internalInstance, partial));
+                    (propName = assign({}, propName, partial)))
+                  : assign(propName, partial));
             }
-            JSCompiler_inline_result$jscomp$0.state = internalInstance;
+            newProps.state = propName;
           }
-        } else internalInstance.queue = null;
-      JSCompiler_inline_result = JSCompiler_inline_result$jscomp$0.render();
+        } else propName.queue = null;
+      JSCompiler_inline_result = newProps.render();
       ref = type.childContextTypes;
       if (null !== ref && void 0 !== ref) {
         keyPath = task.legacyContext;
-        if (
-          "function" !==
-          typeof JSCompiler_inline_result$jscomp$0.getChildContext
-        )
-          type = keyPath;
+        if ("function" !== typeof newProps.getChildContext) type = keyPath;
         else {
-          JSCompiler_inline_result$jscomp$0 =
-            JSCompiler_inline_result$jscomp$0.getChildContext();
-          for (var contextKey in JSCompiler_inline_result$jscomp$0)
+          newProps = newProps.getChildContext();
+          for (var contextKey in newProps)
             if (!(contextKey in ref))
               throw Error(
                 formatProdErrorMessage(
@@ -3920,7 +3919,7 @@ function renderElement(request, task, keyPath, type, props, ref) {
                   contextKey
                 )
               );
-          type = assign({}, keyPath, JSCompiler_inline_result$jscomp$0);
+          type = assign({}, keyPath, newProps);
         }
         task.legacyContext = type;
         renderNodeDestructive(request, task, JSCompiler_inline_result, -1);
@@ -3932,24 +3931,14 @@ function renderElement(request, task, keyPath, type, props, ref) {
           (task.keyPath = type);
       task.componentStack = props;
     } else
-      (JSCompiler_inline_result$jscomp$0 = getMaskedContext(
-        type,
-        task.legacyContext
-      )),
+      (newProps = getMaskedContext(type, task.legacyContext)),
         (contextKey = task.componentStack),
         (task.componentStack = {
           tag: 1,
           parent: task.componentStack,
           type: type
         }),
-        (type = renderWithHooks(
-          request,
-          task,
-          keyPath,
-          type,
-          props,
-          JSCompiler_inline_result$jscomp$0
-        )),
+        (type = renderWithHooks(request, task, keyPath, type, props, newProps)),
         finishFunctionComponent(
           request,
           task,
@@ -3963,9 +3952,9 @@ function renderElement(request, task, keyPath, type, props, ref) {
   else if ("string" === typeof type) {
     contextKey = task.componentStack;
     task.componentStack = createBuiltInComponentStack(task, type);
-    JSCompiler_inline_result$jscomp$0 = task.blockedSegment;
-    if (null === JSCompiler_inline_result$jscomp$0)
-      (JSCompiler_inline_result$jscomp$0 = props.children),
+    newProps = task.blockedSegment;
+    if (null === newProps)
+      (newProps = props.children),
         (JSCompiler_inline_result = task.formatContext),
         (ref = task.keyPath),
         (task.formatContext = getChildFormatContext(
@@ -3974,24 +3963,24 @@ function renderElement(request, task, keyPath, type, props, ref) {
           props
         )),
         (task.keyPath = keyPath),
-        renderNode(request, task, JSCompiler_inline_result$jscomp$0, -1),
+        renderNode(request, task, newProps, -1),
         (task.formatContext = JSCompiler_inline_result),
         (task.keyPath = ref);
     else {
       ref = pushStartInstance(
-        JSCompiler_inline_result$jscomp$0.chunks,
+        newProps.chunks,
         type,
         props,
         request.resumableState,
         request.renderState,
         task.hoistableState,
         task.formatContext,
-        JSCompiler_inline_result$jscomp$0.lastPushedText,
+        newProps.lastPushedText,
         task.isFallback
       );
-      JSCompiler_inline_result$jscomp$0.lastPushedText = !1;
+      newProps.lastPushedText = !1;
       JSCompiler_inline_result = task.formatContext;
-      internalInstance = task.keyPath;
+      propName = task.keyPath;
       task.formatContext = getChildFormatContext(
         JSCompiler_inline_result,
         type,
@@ -4000,9 +3989,9 @@ function renderElement(request, task, keyPath, type, props, ref) {
       task.keyPath = keyPath;
       renderNode(request, task, ref, -1);
       task.formatContext = JSCompiler_inline_result;
-      task.keyPath = internalInstance;
+      task.keyPath = propName;
       a: {
-        keyPath = JSCompiler_inline_result$jscomp$0.chunks;
+        keyPath = newProps.chunks;
         request = request.resumableState;
         switch (type) {
           case "title":
@@ -4038,7 +4027,7 @@ function renderElement(request, task, keyPath, type, props, ref) {
         }
         keyPath.push(endChunkForTag(type));
       }
-      JSCompiler_inline_result$jscomp$0.lastPushedText = !1;
+      newProps.lastPushedText = !1;
     }
     task.componentStack = contextKey;
   } else {
@@ -4098,13 +4087,13 @@ function renderElement(request, task, keyPath, type, props, ref) {
           ref = props.fallback;
           var content = props.children;
           props = new Set();
-          internalInstance = createSuspenseBoundary(request, props);
+          propName = createSuspenseBoundary(request, props);
           null !== request.trackedPostpones &&
-            (internalInstance.trackedContentKeyPath = keyPath);
+            (propName.trackedContentKeyPath = keyPath);
           initialState = createPendingSegment(
             request,
             parentSegment.chunks.length,
-            internalInstance,
+            propName,
             task.formatContext,
             !1,
             !1
@@ -4120,8 +4109,8 @@ function renderElement(request, task, keyPath, type, props, ref) {
             !1
           );
           contentRootSegment.parentFlushed = !0;
-          task.blockedBoundary = internalInstance;
-          task.hoistableState = internalInstance.contentState;
+          task.blockedBoundary = propName;
+          task.hoistableState = propName.contentState;
           task.blockedSegment = contentRootSegment;
           task.keyPath = keyPath;
           try {
@@ -4132,28 +4121,24 @@ function renderElement(request, task, keyPath, type, props, ref) {
                   contentRootSegment.textEmbedded &&
                   contentRootSegment.chunks.push("\x3c!-- --\x3e")),
               (contentRootSegment.status = 1),
-              queueCompletedSegment(internalInstance, contentRootSegment),
-              0 === internalInstance.pendingTasks &&
-                0 === internalInstance.status)
+              queueCompletedSegment(propName, contentRootSegment),
+              0 === propName.pendingTasks && 0 === propName.status)
             ) {
-              internalInstance.status = 1;
+              propName.status = 1;
               task.componentStack = contextType;
               break a;
             }
           } catch (error) {
             (contentRootSegment.status = 4),
-              (internalInstance.status = 4),
-              (JSCompiler_inline_result$jscomp$0 = getThrownInfo(
-                request,
-                task.componentStack
-              )),
+              (propName.status = 4),
+              (newProps = getThrownInfo(request, task.componentStack)),
               (JSCompiler_inline_result = logRecoverableError(
                 request,
                 error,
-                JSCompiler_inline_result$jscomp$0
+                newProps
               )),
-              (internalInstance.errorDigest = JSCompiler_inline_result),
-              untrackBoundary(request, internalInstance);
+              (propName.errorDigest = JSCompiler_inline_result),
+              untrackBoundary(request, propName);
           } finally {
             (task.blockedBoundary = contextKey),
               (task.hoistableState = partial),
@@ -4161,27 +4146,15 @@ function renderElement(request, task, keyPath, type, props, ref) {
               (task.keyPath = oldReplace),
               (task.componentStack = contextType);
           }
-          JSCompiler_inline_result$jscomp$0 = [
-            keyPath[0],
-            "Suspense Fallback",
-            keyPath[2]
-          ];
+          newProps = [keyPath[0], "Suspense Fallback", keyPath[2]];
           JSCompiler_inline_result = request.trackedPostpones;
           null !== JSCompiler_inline_result &&
-            ((contextType = [
-              JSCompiler_inline_result$jscomp$0[1],
-              JSCompiler_inline_result$jscomp$0[2],
-              [],
-              null
-            ]),
-            JSCompiler_inline_result.workingMap.set(
-              JSCompiler_inline_result$jscomp$0,
-              contextType
-            ),
-            5 === internalInstance.status
+            ((contextType = [newProps[1], newProps[2], [], null]),
+            JSCompiler_inline_result.workingMap.set(newProps, contextType),
+            5 === propName.status
               ? (JSCompiler_inline_result.workingMap.get(keyPath)[4] =
                   contextType)
-              : (internalInstance.trackedFallbackNode = contextType));
+              : (propName.trackedFallbackNode = contextType));
           task = createRenderTask(
             request,
             null,
@@ -4189,9 +4162,9 @@ function renderElement(request, task, keyPath, type, props, ref) {
             -1,
             contextKey,
             initialState,
-            internalInstance.fallbackState,
+            propName.fallbackState,
             props,
-            JSCompiler_inline_result$jscomp$0,
+            newProps,
             task.formatContext,
             task.legacyContext,
             task.context,
@@ -4213,18 +4186,16 @@ function renderElement(request, task, keyPath, type, props, ref) {
             type: type.render
           };
           if (enableRefAsProp && "ref" in props)
-            for (internalInstance in ((JSCompiler_inline_result$jscomp$0 = {}),
-            props))
-              "ref" !== internalInstance &&
-                (JSCompiler_inline_result$jscomp$0[internalInstance] =
-                  props[internalInstance]);
-          else JSCompiler_inline_result$jscomp$0 = props;
+            for (initialState in ((newProps = {}), props))
+              "ref" !== initialState &&
+                (newProps[initialState] = props[initialState]);
+          else newProps = props;
           type = renderWithHooks(
             request,
             task,
             keyPath,
             type.render,
-            JSCompiler_inline_result$jscomp$0,
+            newProps,
             ref
           );
           finishFunctionComponent(
@@ -4240,7 +4211,7 @@ function renderElement(request, task, keyPath, type, props, ref) {
           return;
         case REACT_MEMO_TYPE:
           type = type.type;
-          props = resolveDefaultProps(type, props);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, ref);
           return;
         case REACT_PROVIDER_TYPE:
@@ -4261,9 +4232,9 @@ function renderElement(request, task, keyPath, type, props, ref) {
         case REACT_LAZY_TYPE:
           contextKey = task.componentStack;
           task.componentStack = createBuiltInComponentStack(task, "Lazy");
-          JSCompiler_inline_result$jscomp$0 = type._init;
-          type = JSCompiler_inline_result$jscomp$0(type._payload);
-          props = resolveDefaultProps(type, props);
+          newProps = type._init;
+          type = newProps(type._payload);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, void 0);
           task.componentStack = contextKey;
           return;
@@ -5706,4 +5677,4 @@ exports.renderToString = function (children, options) {
     'The server used "renderToString" which does not support Suspense. If you intended for this Suspense boundary to render the fallback content on the server consider throwing an Error somewhere within the Suspense boundary. If you intended to have the server wait for the suspended component please switch to "renderToReadableStream" which supports Suspense on the server'
   );
 };
-exports.version = "19.0.0-www-classic-8a4d889d";
+exports.version = "19.0.0-www-classic-105227cc";
diff --git a/compiled/facebook-www/ReactDOMServer-prod.modern.js b/compiled/facebook-www/ReactDOMServer-prod.modern.js
index 56f223e346..8fdd903192 100644
--- a/compiled/facebook-www/ReactDOMServer-prod.modern.js
+++ b/compiled/facebook-www/ReactDOMServer-prod.modern.js
@@ -133,6 +133,8 @@ var assign = Object.assign,
     dynamicFeatureFlags.enableUseDeferredValueInitialArg,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   hasOwnProperty = Object.prototype.hasOwnProperty,
   VALID_ATTRIBUTE_NAME_REGEX = RegExp(
     "^[:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD][:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD\\-.0-9\\u00B7\\u0300-\\u036F\\u203F-\\u2040]*$"
@@ -2617,16 +2619,16 @@ function createRenderState(resumableState, generateStaticMarkup) {
       "\x3c/script>"
     );
   bootstrapScriptContent = idPrefix + "P:";
-  var JSCompiler_object_inline_segmentPrefix_1616 = idPrefix + "S:";
+  var JSCompiler_object_inline_segmentPrefix_1618 = idPrefix + "S:";
   idPrefix += "B:";
-  var JSCompiler_object_inline_preconnects_1630 = new Set(),
-    JSCompiler_object_inline_fontPreloads_1631 = new Set(),
-    JSCompiler_object_inline_highImagePreloads_1632 = new Set(),
-    JSCompiler_object_inline_styles_1633 = new Map(),
-    JSCompiler_object_inline_bootstrapScripts_1634 = new Set(),
-    JSCompiler_object_inline_scripts_1635 = new Set(),
-    JSCompiler_object_inline_bulkPreloads_1636 = new Set(),
-    JSCompiler_object_inline_preloads_1637 = {
+  var JSCompiler_object_inline_preconnects_1632 = new Set(),
+    JSCompiler_object_inline_fontPreloads_1633 = new Set(),
+    JSCompiler_object_inline_highImagePreloads_1634 = new Set(),
+    JSCompiler_object_inline_styles_1635 = new Map(),
+    JSCompiler_object_inline_bootstrapScripts_1636 = new Set(),
+    JSCompiler_object_inline_scripts_1637 = new Set(),
+    JSCompiler_object_inline_bulkPreloads_1638 = new Set(),
+    JSCompiler_object_inline_preloads_1639 = {
       images: new Map(),
       stylesheets: new Map(),
       scripts: new Map(),
@@ -2663,7 +2665,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
       scriptConfig.moduleScriptResources[href] = null;
       scriptConfig = [];
       pushLinkImpl(scriptConfig, props);
-      JSCompiler_object_inline_bootstrapScripts_1634.add(scriptConfig);
+      JSCompiler_object_inline_bootstrapScripts_1636.add(scriptConfig);
       bootstrapChunks.push('<script src="', escapeTextForBrowser(src));
       "string" === typeof integrity &&
         bootstrapChunks.push('" integrity="', escapeTextForBrowser(integrity));
@@ -2704,7 +2706,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
         (props.moduleScriptResources[scriptConfig] = null),
         (props = []),
         pushLinkImpl(props, integrity),
-        JSCompiler_object_inline_bootstrapScripts_1634.add(props),
+        JSCompiler_object_inline_bootstrapScripts_1636.add(props),
         bootstrapChunks.push(
           '<script type="module" src="',
           escapeTextForBrowser(i)
@@ -2719,7 +2721,7 @@ function createRenderState(resumableState, generateStaticMarkup) {
         bootstrapChunks.push('" async="">\x3c/script>');
   return {
     placeholderPrefix: bootstrapScriptContent,
-    segmentPrefix: JSCompiler_object_inline_segmentPrefix_1616,
+    segmentPrefix: JSCompiler_object_inline_segmentPrefix_1618,
     boundaryPrefix: idPrefix,
     startInlineScript: "<script>",
     htmlChunks: null,
@@ -2739,14 +2741,14 @@ function createRenderState(resumableState, generateStaticMarkup) {
     charsetChunks: [],
     viewportChunks: [],
     hoistableChunks: [],
-    preconnects: JSCompiler_object_inline_preconnects_1630,
-    fontPreloads: JSCompiler_object_inline_fontPreloads_1631,
-    highImagePreloads: JSCompiler_object_inline_highImagePreloads_1632,
-    styles: JSCompiler_object_inline_styles_1633,
-    bootstrapScripts: JSCompiler_object_inline_bootstrapScripts_1634,
-    scripts: JSCompiler_object_inline_scripts_1635,
-    bulkPreloads: JSCompiler_object_inline_bulkPreloads_1636,
-    preloads: JSCompiler_object_inline_preloads_1637,
+    preconnects: JSCompiler_object_inline_preconnects_1632,
+    fontPreloads: JSCompiler_object_inline_fontPreloads_1633,
+    highImagePreloads: JSCompiler_object_inline_highImagePreloads_1634,
+    styles: JSCompiler_object_inline_styles_1635,
+    bootstrapScripts: JSCompiler_object_inline_bootstrapScripts_1636,
+    scripts: JSCompiler_object_inline_scripts_1637,
+    bulkPreloads: JSCompiler_object_inline_bulkPreloads_1638,
+    preloads: JSCompiler_object_inline_preloads_1639,
     stylesToHoist: !1,
     generateStaticMarkup: generateStaticMarkup
   };
@@ -3748,7 +3750,8 @@ function finishFunctionComponent(
     : renderNodeDestructive(request, task, children, -1);
   task.keyPath = actionStateCount;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -3794,109 +3797,108 @@ function renderContextProvider(request, task, keyPath, context, props) {
 function renderElement(request, task, keyPath, type, props, ref) {
   if ("function" === typeof type)
     if (type.prototype && type.prototype.isReactComponent) {
+      var JSCompiler_inline_result = props;
+      var defaultProps = type.defaultProps;
+      if (defaultProps && disableDefaultPropsExceptForClasses) {
+        JSCompiler_inline_result = assign({}, JSCompiler_inline_result, props);
+        for (var propName in defaultProps)
+          void 0 === JSCompiler_inline_result[propName] &&
+            (JSCompiler_inline_result[propName] = defaultProps[propName]);
+      }
       enableRefAsProp &&
-        "ref" in props &&
-        ((props = assign({}, props)), delete props.ref);
-      ref = props;
+        "ref" in JSCompiler_inline_result &&
+        (JSCompiler_inline_result === props &&
+          (JSCompiler_inline_result = assign({}, JSCompiler_inline_result)),
+        delete JSCompiler_inline_result.ref);
       props = task.componentStack;
       task.componentStack = { tag: 2, parent: task.componentStack, type: type };
-      var JSCompiler_inline_result = emptyContextObject;
+      defaultProps = emptyContextObject;
+      ref = type.contextType;
+      "object" === typeof ref &&
+        null !== ref &&
+        (defaultProps = ref._currentValue2);
+      defaultProps = new type(JSCompiler_inline_result, defaultProps);
+      propName = void 0 !== defaultProps.state ? defaultProps.state : null;
+      defaultProps.updater = classComponentUpdater;
+      defaultProps.props = JSCompiler_inline_result;
+      defaultProps.state = propName;
+      ref = { queue: [], replace: !1 };
+      defaultProps._reactInternals = ref;
       var contextType = type.contextType;
-      "object" === typeof contextType &&
-        null !== contextType &&
-        (JSCompiler_inline_result = contextType._currentValue2);
-      JSCompiler_inline_result = new type(ref, JSCompiler_inline_result);
-      var initialState =
-        void 0 !== JSCompiler_inline_result.state
-          ? JSCompiler_inline_result.state
-          : null;
-      JSCompiler_inline_result.updater = classComponentUpdater;
-      JSCompiler_inline_result.props = ref;
-      JSCompiler_inline_result.state = initialState;
-      contextType = { queue: [], replace: !1 };
-      JSCompiler_inline_result._reactInternals = contextType;
-      var contextType$jscomp$0 = type.contextType;
-      JSCompiler_inline_result.context =
-        "object" === typeof contextType$jscomp$0 &&
-        null !== contextType$jscomp$0
-          ? contextType$jscomp$0._currentValue2
+      defaultProps.context =
+        "object" === typeof contextType && null !== contextType
+          ? contextType._currentValue2
           : emptyContextObject;
-      contextType$jscomp$0 = type.getDerivedStateFromProps;
-      "function" === typeof contextType$jscomp$0 &&
-        ((contextType$jscomp$0 = contextType$jscomp$0(ref, initialState)),
-        (initialState =
-          null === contextType$jscomp$0 || void 0 === contextType$jscomp$0
-            ? initialState
-            : assign({}, initialState, contextType$jscomp$0)),
-        (JSCompiler_inline_result.state = initialState));
+      contextType = type.getDerivedStateFromProps;
+      "function" === typeof contextType &&
+        ((contextType = contextType(JSCompiler_inline_result, propName)),
+        (propName =
+          null === contextType || void 0 === contextType
+            ? propName
+            : assign({}, propName, contextType)),
+        (defaultProps.state = propName));
       if (
         "function" !== typeof type.getDerivedStateFromProps &&
-        "function" !==
-          typeof JSCompiler_inline_result.getSnapshotBeforeUpdate &&
-        ("function" ===
-          typeof JSCompiler_inline_result.UNSAFE_componentWillMount ||
-          "function" === typeof JSCompiler_inline_result.componentWillMount)
+        "function" !== typeof defaultProps.getSnapshotBeforeUpdate &&
+        ("function" === typeof defaultProps.UNSAFE_componentWillMount ||
+          "function" === typeof defaultProps.componentWillMount)
       )
         if (
-          ((type = JSCompiler_inline_result.state),
-          "function" === typeof JSCompiler_inline_result.componentWillMount &&
-            JSCompiler_inline_result.componentWillMount(),
-          "function" ===
-            typeof JSCompiler_inline_result.UNSAFE_componentWillMount &&
-            JSCompiler_inline_result.UNSAFE_componentWillMount(),
-          type !== JSCompiler_inline_result.state &&
+          ((type = defaultProps.state),
+          "function" === typeof defaultProps.componentWillMount &&
+            defaultProps.componentWillMount(),
+          "function" === typeof defaultProps.UNSAFE_componentWillMount &&
+            defaultProps.UNSAFE_componentWillMount(),
+          type !== defaultProps.state &&
             classComponentUpdater.enqueueReplaceState(
-              JSCompiler_inline_result,
-              JSCompiler_inline_result.state,
+              defaultProps,
+              defaultProps.state,
               null
             ),
-          null !== contextType.queue && 0 < contextType.queue.length)
+          null !== ref.queue && 0 < ref.queue.length)
         )
           if (
-            ((type = contextType.queue),
-            (contextType$jscomp$0 = contextType.replace),
-            (contextType.queue = null),
-            (contextType.replace = !1),
-            contextType$jscomp$0 && 1 === type.length)
+            ((type = ref.queue),
+            (contextType = ref.replace),
+            (ref.queue = null),
+            (ref.replace = !1),
+            contextType && 1 === type.length)
           )
-            JSCompiler_inline_result.state = type[0];
+            defaultProps.state = type[0];
           else {
-            contextType = contextType$jscomp$0
-              ? type[0]
-              : JSCompiler_inline_result.state;
-            initialState = !0;
+            ref = contextType ? type[0] : defaultProps.state;
+            propName = !0;
             for (
-              contextType$jscomp$0 = contextType$jscomp$0 ? 1 : 0;
-              contextType$jscomp$0 < type.length;
-              contextType$jscomp$0++
+              contextType = contextType ? 1 : 0;
+              contextType < type.length;
+              contextType++
             ) {
-              var partial = type[contextType$jscomp$0];
+              var partial = type[contextType];
               partial =
                 "function" === typeof partial
                   ? partial.call(
-                      JSCompiler_inline_result,
-                      contextType,
+                      defaultProps,
                       ref,
+                      JSCompiler_inline_result,
                       void 0
                     )
                   : partial;
               null != partial &&
-                (initialState
-                  ? ((initialState = !1),
-                    (contextType = assign({}, contextType, partial)))
-                  : assign(contextType, partial));
+                (propName
+                  ? ((propName = !1), (ref = assign({}, ref, partial)))
+                  : assign(ref, partial));
             }
-            JSCompiler_inline_result.state = contextType;
+            defaultProps.state = ref;
           }
-        else contextType.queue = null;
-      type = JSCompiler_inline_result.render();
-      ref = task.keyPath;
+        else ref.queue = null;
+      type = defaultProps.render();
+      JSCompiler_inline_result = task.keyPath;
       task.keyPath = keyPath;
       renderNodeDestructive(request, task, type, -1);
-      task.keyPath = ref;
+      task.keyPath = JSCompiler_inline_result;
       task.componentStack = props;
     } else
-      (ref = task.componentStack),
+      (JSCompiler_inline_result = task.componentStack),
         (task.componentStack = {
           tag: 1,
           parent: task.componentStack,
@@ -3912,42 +3914,42 @@ function renderElement(request, task, keyPath, type, props, ref) {
           actionStateCounter,
           actionStateMatchingIndex
         ),
-        (task.componentStack = ref);
+        (task.componentStack = JSCompiler_inline_result);
   else if ("string" === typeof type) {
-    ref = task.componentStack;
+    JSCompiler_inline_result = task.componentStack;
     task.componentStack = createBuiltInComponentStack(task, type);
-    JSCompiler_inline_result = task.blockedSegment;
-    if (null === JSCompiler_inline_result)
-      (JSCompiler_inline_result = props.children),
-        (contextType = task.formatContext),
-        (initialState = task.keyPath),
-        (task.formatContext = getChildFormatContext(contextType, type, props)),
+    defaultProps = task.blockedSegment;
+    if (null === defaultProps)
+      (defaultProps = props.children),
+        (ref = task.formatContext),
+        (propName = task.keyPath),
+        (task.formatContext = getChildFormatContext(ref, type, props)),
         (task.keyPath = keyPath),
-        renderNode(request, task, JSCompiler_inline_result, -1),
-        (task.formatContext = contextType),
-        (task.keyPath = initialState);
+        renderNode(request, task, defaultProps, -1),
+        (task.formatContext = ref),
+        (task.keyPath = propName);
     else {
-      initialState = pushStartInstance(
-        JSCompiler_inline_result.chunks,
+      propName = pushStartInstance(
+        defaultProps.chunks,
         type,
         props,
         request.resumableState,
         request.renderState,
         task.hoistableState,
         task.formatContext,
-        JSCompiler_inline_result.lastPushedText,
+        defaultProps.lastPushedText,
         task.isFallback
       );
-      JSCompiler_inline_result.lastPushedText = !1;
-      contextType = task.formatContext;
-      contextType$jscomp$0 = task.keyPath;
-      task.formatContext = getChildFormatContext(contextType, type, props);
+      defaultProps.lastPushedText = !1;
+      ref = task.formatContext;
+      contextType = task.keyPath;
+      task.formatContext = getChildFormatContext(ref, type, props);
       task.keyPath = keyPath;
-      renderNode(request, task, initialState, -1);
-      task.formatContext = contextType;
-      task.keyPath = contextType$jscomp$0;
+      renderNode(request, task, propName, -1);
+      task.formatContext = ref;
+      task.keyPath = contextType;
       a: {
-        keyPath = JSCompiler_inline_result.chunks;
+        keyPath = defaultProps.chunks;
         request = request.resumableState;
         switch (type) {
           case "title":
@@ -3970,22 +3972,22 @@ function renderElement(request, task, keyPath, type, props, ref) {
           case "wbr":
             break a;
           case "body":
-            if (1 >= contextType.insertionMode) {
+            if (1 >= ref.insertionMode) {
               request.hasBody = !0;
               break a;
             }
             break;
           case "html":
-            if (0 === contextType.insertionMode) {
+            if (0 === ref.insertionMode) {
               request.hasHtml = !0;
               break a;
             }
         }
         keyPath.push(endChunkForTag(type));
       }
-      JSCompiler_inline_result.lastPushedText = !1;
+      defaultProps.lastPushedText = !1;
     }
-    task.componentStack = ref;
+    task.componentStack = JSCompiler_inline_result;
   } else {
     switch (type) {
       case REACT_LEGACY_HIDDEN_TYPE:
@@ -4008,10 +4010,10 @@ function renderElement(request, task, keyPath, type, props, ref) {
       case REACT_SUSPENSE_LIST_TYPE:
         type = task.componentStack;
         task.componentStack = createBuiltInComponentStack(task, "SuspenseList");
-        ref = task.keyPath;
+        JSCompiler_inline_result = task.keyPath;
         task.keyPath = keyPath;
         renderNodeDestructive(request, task, props.children, -1);
-        task.keyPath = ref;
+        task.keyPath = JSCompiler_inline_result;
         task.componentStack = type;
         return;
       case REACT_SCOPE_TYPE:
@@ -4040,16 +4042,16 @@ function renderElement(request, task, keyPath, type, props, ref) {
           ref = task.blockedBoundary;
           var parentHoistableState = task.hoistableState,
             parentSegment = task.blockedSegment;
-          JSCompiler_inline_result = props.fallback;
+          propName = props.fallback;
           var content = props.children;
           props = new Set();
-          contextType$jscomp$0 = createSuspenseBoundary(request, props);
+          contextType = createSuspenseBoundary(request, props);
           null !== request.trackedPostpones &&
-            (contextType$jscomp$0.trackedContentKeyPath = keyPath);
+            (contextType.trackedContentKeyPath = keyPath);
           partial = createPendingSegment(
             request,
             parentSegment.chunks.length,
-            contextType$jscomp$0,
+            contextType,
             task.formatContext,
             !1,
             !1
@@ -4065,8 +4067,8 @@ function renderElement(request, task, keyPath, type, props, ref) {
             !1
           );
           contentRootSegment.parentFlushed = !0;
-          task.blockedBoundary = contextType$jscomp$0;
-          task.hoistableState = contextType$jscomp$0.contentState;
+          task.blockedBoundary = contextType;
+          task.hoistableState = contextType.contentState;
           task.blockedSegment = contentRootSegment;
           task.keyPath = keyPath;
           try {
@@ -4077,21 +4079,27 @@ function renderElement(request, task, keyPath, type, props, ref) {
                   contentRootSegment.textEmbedded &&
                   contentRootSegment.chunks.push("\x3c!-- --\x3e")),
               (contentRootSegment.status = 1),
-              queueCompletedSegment(contextType$jscomp$0, contentRootSegment),
-              0 === contextType$jscomp$0.pendingTasks &&
-                0 === contextType$jscomp$0.status)
+              queueCompletedSegment(contextType, contentRootSegment),
+              0 === contextType.pendingTasks && 0 === contextType.status)
             ) {
-              contextType$jscomp$0.status = 1;
+              contextType.status = 1;
               task.componentStack = previousComponentStack;
               break a;
             }
           } catch (error) {
             (contentRootSegment.status = 4),
-              (contextType$jscomp$0.status = 4),
-              (contextType = getThrownInfo(request, task.componentStack)),
-              (initialState = logRecoverableError(request, error, contextType)),
-              (contextType$jscomp$0.errorDigest = initialState),
-              untrackBoundary(request, contextType$jscomp$0);
+              (contextType.status = 4),
+              (JSCompiler_inline_result = getThrownInfo(
+                request,
+                task.componentStack
+              )),
+              (defaultProps = logRecoverableError(
+                request,
+                error,
+                JSCompiler_inline_result
+              )),
+              (contextType.errorDigest = defaultProps),
+              untrackBoundary(request, contextType);
           } finally {
             (task.blockedBoundary = ref),
               (task.hoistableState = parentHoistableState),
@@ -4099,31 +4107,37 @@ function renderElement(request, task, keyPath, type, props, ref) {
               (task.keyPath = prevKeyPath),
               (task.componentStack = previousComponentStack);
           }
-          contextType = [keyPath[0], "Suspense Fallback", keyPath[2]];
-          initialState = request.trackedPostpones;
-          null !== initialState &&
+          JSCompiler_inline_result = [
+            keyPath[0],
+            "Suspense Fallback",
+            keyPath[2]
+          ];
+          defaultProps = request.trackedPostpones;
+          null !== defaultProps &&
             ((previousComponentStack = [
-              contextType[1],
-              contextType[2],
+              JSCompiler_inline_result[1],
+              JSCompiler_inline_result[2],
               [],
               null
             ]),
-            initialState.workingMap.set(contextType, previousComponentStack),
-            5 === contextType$jscomp$0.status
-              ? (initialState.workingMap.get(keyPath)[4] =
+            defaultProps.workingMap.set(
+              JSCompiler_inline_result,
+              previousComponentStack
+            ),
+            5 === contextType.status
+              ? (defaultProps.workingMap.get(keyPath)[4] =
                   previousComponentStack)
-              : (contextType$jscomp$0.trackedFallbackNode =
-                  previousComponentStack));
+              : (contextType.trackedFallbackNode = previousComponentStack));
           task = createRenderTask(
             request,
             null,
-            JSCompiler_inline_result,
+            propName,
             -1,
             ref,
             partial,
-            contextType$jscomp$0.fallbackState,
+            contextType.fallbackState,
             props,
-            contextType,
+            JSCompiler_inline_result,
             task.formatContext,
             task.legacyContext,
             task.context,
@@ -4138,24 +4152,23 @@ function renderElement(request, task, keyPath, type, props, ref) {
     if ("object" === typeof type && null !== type)
       switch (type.$$typeof) {
         case REACT_FORWARD_REF_TYPE:
-          contextType = task.componentStack;
+          JSCompiler_inline_result = task.componentStack;
           task.componentStack = {
             tag: 1,
             parent: task.componentStack,
             type: type.render
           };
           if (enableRefAsProp && "ref" in props)
-            for (JSCompiler_inline_result in ((initialState = {}), props))
-              "ref" !== JSCompiler_inline_result &&
-                (initialState[JSCompiler_inline_result] =
-                  props[JSCompiler_inline_result]);
-          else initialState = props;
+            for (contextType in ((defaultProps = {}), props))
+              "ref" !== contextType &&
+                (defaultProps[contextType] = props[contextType]);
+          else defaultProps = props;
           props = renderWithHooks(
             request,
             task,
             keyPath,
             type.render,
-            initialState,
+            defaultProps,
             ref
           );
           finishFunctionComponent(
@@ -4167,11 +4180,11 @@ function renderElement(request, task, keyPath, type, props, ref) {
             actionStateCounter,
             actionStateMatchingIndex
           );
-          task.componentStack = contextType;
+          task.componentStack = JSCompiler_inline_result;
           return;
         case REACT_MEMO_TYPE:
           type = type.type;
-          props = resolveDefaultProps(type, props);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, ref);
           return;
         case REACT_PROVIDER_TYPE:
@@ -4190,13 +4203,13 @@ function renderElement(request, task, keyPath, type, props, ref) {
             return;
           }
         case REACT_LAZY_TYPE:
-          ref = task.componentStack;
+          JSCompiler_inline_result = task.componentStack;
           task.componentStack = createBuiltInComponentStack(task, "Lazy");
-          JSCompiler_inline_result = type._init;
-          type = JSCompiler_inline_result(type._payload);
-          props = resolveDefaultProps(type, props);
+          defaultProps = type._init;
+          type = defaultProps(type._payload);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, void 0);
-          task.componentStack = ref;
+          task.componentStack = JSCompiler_inline_result;
           return;
       }
     throw Error(
@@ -5637,4 +5650,4 @@ exports.renderToString = function (children, options) {
     'The server used "renderToString" which does not support Suspense. If you intended for this Suspense boundary to render the fallback content on the server consider throwing an Error somewhere within the Suspense boundary. If you intended to have the server wait for the suspended component please switch to "renderToReadableStream" which supports Suspense on the server'
   );
 };
-exports.version = "19.0.0-www-modern-97b251b2";
+exports.version = "19.0.0-www-modern-09c7873c";
diff --git a/compiled/facebook-www/ReactDOMServerStreaming-dev.modern.js b/compiled/facebook-www/ReactDOMServerStreaming-dev.modern.js
index aa91ca1b82..6b8fd23c87 100644
--- a/compiled/facebook-www/ReactDOMServerStreaming-dev.modern.js
+++ b/compiled/facebook-www/ReactDOMServerStreaming-dev.modern.js
@@ -675,8 +675,9 @@ if (__DEV__) {
       enableUseDeferredValueInitialArg =
         dynamicFeatureFlags.enableUseDeferredValueInitialArg,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
 
     // $FlowFixMe[method-unbinding]
     var hasOwnProperty = Object.prototype.hasOwnProperty;
@@ -11779,12 +11780,27 @@ if (__DEV__) {
     }
 
     function resolveClassComponentProps(Component, baseProps) {
-      var newProps = baseProps; // TODO: This is where defaultProps should be resolved, too.
+      var newProps = baseProps; // Resolve default props. Taken from old JSX runtime, where this used to live.
+
+      var defaultProps = Component.defaultProps;
+
+      if (defaultProps && disableDefaultPropsExceptForClasses) {
+        newProps = assign({}, newProps, baseProps);
+
+        for (var propName in defaultProps) {
+          if (newProps[propName] === undefined) {
+            newProps[propName] = defaultProps[propName];
+          }
+        }
+      }
 
       if (enableRefAsProp) {
         // Remove ref from the props object, if it exists.
         if ("ref" in newProps) {
-          newProps = assign({}, newProps);
+          if (newProps === baseProps) {
+            newProps = assign({}, newProps);
+          }
+
           delete newProps.ref;
         }
       }
@@ -11961,7 +11977,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
@@ -12008,7 +12027,13 @@ if (__DEV__) {
       }
     }
 
-    function resolveDefaultProps(Component, baseProps) {
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -12074,7 +12099,10 @@ if (__DEV__) {
 
     function renderMemo(request, task, keyPath, type, props, ref) {
       var innerType = type.type;
-      var resolvedProps = resolveDefaultProps(innerType, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        innerType,
+        props
+      );
       renderElement(request, task, keyPath, innerType, resolvedProps, ref);
     }
 
@@ -12138,7 +12166,10 @@ if (__DEV__) {
       var payload = lazyComponent._payload;
       var init = lazyComponent._init;
       var Component = init(payload);
-      var resolvedProps = resolveDefaultProps(Component, props);
+      var resolvedProps = resolveDefaultPropsOnNonClassComponent(
+        Component,
+        props
+      );
       renderElement(request, task, keyPath, Component, resolvedProps, ref);
       task.componentStack = previousComponentStack;
     }
diff --git a/compiled/facebook-www/ReactDOMServerStreaming-prod.modern.js b/compiled/facebook-www/ReactDOMServerStreaming-prod.modern.js
index 3db2712a1e..db7d142e2e 100644
--- a/compiled/facebook-www/ReactDOMServerStreaming-prod.modern.js
+++ b/compiled/facebook-www/ReactDOMServerStreaming-prod.modern.js
@@ -125,6 +125,8 @@ var assign = Object.assign,
     dynamicFeatureFlags.enableUseDeferredValueInitialArg,
   enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   hasOwnProperty = Object.prototype.hasOwnProperty,
   VALID_ATTRIBUTE_NAME_REGEX = RegExp(
     "^[:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD][:A-Z_a-z\\u00C0-\\u00D6\\u00D8-\\u00F6\\u00F8-\\u02FF\\u0370-\\u037D\\u037F-\\u1FFF\\u200C-\\u200D\\u2070-\\u218F\\u2C00-\\u2FEF\\u3001-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFFD\\-.0-9\\u00B7\\u0300-\\u036F\\u203F-\\u2040]*$"
@@ -3569,7 +3571,8 @@ function finishFunctionComponent(
     : renderNodeDestructive(request, task, children, -1);
   task.keyPath = actionStateCount;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -3618,109 +3621,108 @@ function renderContextProvider(request, task, keyPath, context, props) {
 function renderElement(request, task, keyPath, type, props, ref) {
   if ("function" === typeof type)
     if (type.prototype && type.prototype.isReactComponent) {
+      var JSCompiler_inline_result = props;
+      var defaultProps = type.defaultProps;
+      if (defaultProps && disableDefaultPropsExceptForClasses) {
+        JSCompiler_inline_result = assign({}, JSCompiler_inline_result, props);
+        for (var propName in defaultProps)
+          void 0 === JSCompiler_inline_result[propName] &&
+            (JSCompiler_inline_result[propName] = defaultProps[propName]);
+      }
       enableRefAsProp &&
-        "ref" in props &&
-        ((props = assign({}, props)), delete props.ref);
-      ref = props;
+        "ref" in JSCompiler_inline_result &&
+        (JSCompiler_inline_result === props &&
+          (JSCompiler_inline_result = assign({}, JSCompiler_inline_result)),
+        delete JSCompiler_inline_result.ref);
       props = task.componentStack;
       task.componentStack = { tag: 2, parent: task.componentStack, type: type };
-      var JSCompiler_inline_result = emptyContextObject;
+      defaultProps = emptyContextObject;
+      ref = type.contextType;
+      "object" === typeof ref &&
+        null !== ref &&
+        (defaultProps = ref._currentValue);
+      defaultProps = new type(JSCompiler_inline_result, defaultProps);
+      propName = void 0 !== defaultProps.state ? defaultProps.state : null;
+      defaultProps.updater = classComponentUpdater;
+      defaultProps.props = JSCompiler_inline_result;
+      defaultProps.state = propName;
+      ref = { queue: [], replace: !1 };
+      defaultProps._reactInternals = ref;
       var contextType = type.contextType;
-      "object" === typeof contextType &&
-        null !== contextType &&
-        (JSCompiler_inline_result = contextType._currentValue);
-      JSCompiler_inline_result = new type(ref, JSCompiler_inline_result);
-      var initialState =
-        void 0 !== JSCompiler_inline_result.state
-          ? JSCompiler_inline_result.state
-          : null;
-      JSCompiler_inline_result.updater = classComponentUpdater;
-      JSCompiler_inline_result.props = ref;
-      JSCompiler_inline_result.state = initialState;
-      contextType = { queue: [], replace: !1 };
-      JSCompiler_inline_result._reactInternals = contextType;
-      var contextType$jscomp$0 = type.contextType;
-      JSCompiler_inline_result.context =
-        "object" === typeof contextType$jscomp$0 &&
-        null !== contextType$jscomp$0
-          ? contextType$jscomp$0._currentValue
+      defaultProps.context =
+        "object" === typeof contextType && null !== contextType
+          ? contextType._currentValue
           : emptyContextObject;
-      contextType$jscomp$0 = type.getDerivedStateFromProps;
-      "function" === typeof contextType$jscomp$0 &&
-        ((contextType$jscomp$0 = contextType$jscomp$0(ref, initialState)),
-        (initialState =
-          null === contextType$jscomp$0 || void 0 === contextType$jscomp$0
-            ? initialState
-            : assign({}, initialState, contextType$jscomp$0)),
-        (JSCompiler_inline_result.state = initialState));
+      contextType = type.getDerivedStateFromProps;
+      "function" === typeof contextType &&
+        ((contextType = contextType(JSCompiler_inline_result, propName)),
+        (propName =
+          null === contextType || void 0 === contextType
+            ? propName
+            : assign({}, propName, contextType)),
+        (defaultProps.state = propName));
       if (
         "function" !== typeof type.getDerivedStateFromProps &&
-        "function" !==
-          typeof JSCompiler_inline_result.getSnapshotBeforeUpdate &&
-        ("function" ===
-          typeof JSCompiler_inline_result.UNSAFE_componentWillMount ||
-          "function" === typeof JSCompiler_inline_result.componentWillMount)
+        "function" !== typeof defaultProps.getSnapshotBeforeUpdate &&
+        ("function" === typeof defaultProps.UNSAFE_componentWillMount ||
+          "function" === typeof defaultProps.componentWillMount)
       )
         if (
-          ((type = JSCompiler_inline_result.state),
-          "function" === typeof JSCompiler_inline_result.componentWillMount &&
-            JSCompiler_inline_result.componentWillMount(),
-          "function" ===
-            typeof JSCompiler_inline_result.UNSAFE_componentWillMount &&
-            JSCompiler_inline_result.UNSAFE_componentWillMount(),
-          type !== JSCompiler_inline_result.state &&
+          ((type = defaultProps.state),
+          "function" === typeof defaultProps.componentWillMount &&
+            defaultProps.componentWillMount(),
+          "function" === typeof defaultProps.UNSAFE_componentWillMount &&
+            defaultProps.UNSAFE_componentWillMount(),
+          type !== defaultProps.state &&
             classComponentUpdater.enqueueReplaceState(
-              JSCompiler_inline_result,
-              JSCompiler_inline_result.state,
+              defaultProps,
+              defaultProps.state,
               null
             ),
-          null !== contextType.queue && 0 < contextType.queue.length)
+          null !== ref.queue && 0 < ref.queue.length)
         )
           if (
-            ((type = contextType.queue),
-            (contextType$jscomp$0 = contextType.replace),
-            (contextType.queue = null),
-            (contextType.replace = !1),
-            contextType$jscomp$0 && 1 === type.length)
+            ((type = ref.queue),
+            (contextType = ref.replace),
+            (ref.queue = null),
+            (ref.replace = !1),
+            contextType && 1 === type.length)
           )
-            JSCompiler_inline_result.state = type[0];
+            defaultProps.state = type[0];
           else {
-            contextType = contextType$jscomp$0
-              ? type[0]
-              : JSCompiler_inline_result.state;
-            initialState = !0;
+            ref = contextType ? type[0] : defaultProps.state;
+            propName = !0;
             for (
-              contextType$jscomp$0 = contextType$jscomp$0 ? 1 : 0;
-              contextType$jscomp$0 < type.length;
-              contextType$jscomp$0++
+              contextType = contextType ? 1 : 0;
+              contextType < type.length;
+              contextType++
             ) {
-              var partial = type[contextType$jscomp$0];
+              var partial = type[contextType];
               partial =
                 "function" === typeof partial
                   ? partial.call(
-                      JSCompiler_inline_result,
-                      contextType,
+                      defaultProps,
                       ref,
+                      JSCompiler_inline_result,
                       void 0
                     )
                   : partial;
               null != partial &&
-                (initialState
-                  ? ((initialState = !1),
-                    (contextType = assign({}, contextType, partial)))
-                  : assign(contextType, partial));
+                (propName
+                  ? ((propName = !1), (ref = assign({}, ref, partial)))
+                  : assign(ref, partial));
             }
-            JSCompiler_inline_result.state = contextType;
+            defaultProps.state = ref;
           }
-        else contextType.queue = null;
-      type = JSCompiler_inline_result.render();
-      ref = task.keyPath;
+        else ref.queue = null;
+      type = defaultProps.render();
+      JSCompiler_inline_result = task.keyPath;
       task.keyPath = keyPath;
       renderNodeDestructive(request, task, type, -1);
-      task.keyPath = ref;
+      task.keyPath = JSCompiler_inline_result;
       task.componentStack = props;
     } else
-      (ref = task.componentStack),
+      (JSCompiler_inline_result = task.componentStack),
         (task.componentStack = {
           tag: 1,
           parent: task.componentStack,
@@ -3736,42 +3738,42 @@ function renderElement(request, task, keyPath, type, props, ref) {
           actionStateCounter,
           actionStateMatchingIndex
         ),
-        (task.componentStack = ref);
+        (task.componentStack = JSCompiler_inline_result);
   else if ("string" === typeof type) {
-    ref = task.componentStack;
+    JSCompiler_inline_result = task.componentStack;
     task.componentStack = createBuiltInComponentStack(task, type);
-    JSCompiler_inline_result = task.blockedSegment;
-    if (null === JSCompiler_inline_result)
-      (JSCompiler_inline_result = props.children),
-        (contextType = task.formatContext),
-        (initialState = task.keyPath),
-        (task.formatContext = getChildFormatContext(contextType, type, props)),
+    defaultProps = task.blockedSegment;
+    if (null === defaultProps)
+      (defaultProps = props.children),
+        (ref = task.formatContext),
+        (propName = task.keyPath),
+        (task.formatContext = getChildFormatContext(ref, type, props)),
         (task.keyPath = keyPath),
-        renderNode(request, task, JSCompiler_inline_result, -1),
-        (task.formatContext = contextType),
-        (task.keyPath = initialState);
+        renderNode(request, task, defaultProps, -1),
+        (task.formatContext = ref),
+        (task.keyPath = propName);
     else {
-      initialState = pushStartInstance(
-        JSCompiler_inline_result.chunks,
+      propName = pushStartInstance(
+        defaultProps.chunks,
         type,
         props,
         request.resumableState,
         request.renderState,
         task.hoistableState,
         task.formatContext,
-        JSCompiler_inline_result.lastPushedText,
+        defaultProps.lastPushedText,
         task.isFallback
       );
-      JSCompiler_inline_result.lastPushedText = !1;
-      contextType = task.formatContext;
-      contextType$jscomp$0 = task.keyPath;
-      task.formatContext = getChildFormatContext(contextType, type, props);
+      defaultProps.lastPushedText = !1;
+      ref = task.formatContext;
+      contextType = task.keyPath;
+      task.formatContext = getChildFormatContext(ref, type, props);
       task.keyPath = keyPath;
-      renderNode(request, task, initialState, -1);
-      task.formatContext = contextType;
-      task.keyPath = contextType$jscomp$0;
+      renderNode(request, task, propName, -1);
+      task.formatContext = ref;
+      task.keyPath = contextType;
       a: {
-        keyPath = JSCompiler_inline_result.chunks;
+        keyPath = defaultProps.chunks;
         request = request.resumableState;
         switch (type) {
           case "title":
@@ -3794,22 +3796,22 @@ function renderElement(request, task, keyPath, type, props, ref) {
           case "wbr":
             break a;
           case "body":
-            if (1 >= contextType.insertionMode) {
+            if (1 >= ref.insertionMode) {
               request.hasBody = !0;
               break a;
             }
             break;
           case "html":
-            if (0 === contextType.insertionMode) {
+            if (0 === ref.insertionMode) {
               request.hasHtml = !0;
               break a;
             }
         }
         keyPath.push(endChunkForTag(type));
       }
-      JSCompiler_inline_result.lastPushedText = !1;
+      defaultProps.lastPushedText = !1;
     }
-    task.componentStack = ref;
+    task.componentStack = JSCompiler_inline_result;
   } else {
     switch (type) {
       case REACT_LEGACY_HIDDEN_TYPE:
@@ -3832,10 +3834,10 @@ function renderElement(request, task, keyPath, type, props, ref) {
       case REACT_SUSPENSE_LIST_TYPE:
         type = task.componentStack;
         task.componentStack = createBuiltInComponentStack(task, "SuspenseList");
-        ref = task.keyPath;
+        JSCompiler_inline_result = task.keyPath;
         task.keyPath = keyPath;
         renderNodeDestructive(request, task, props.children, -1);
-        task.keyPath = ref;
+        task.keyPath = JSCompiler_inline_result;
         task.componentStack = type;
         return;
       case REACT_SCOPE_TYPE:
@@ -3864,16 +3866,16 @@ function renderElement(request, task, keyPath, type, props, ref) {
           ref = task.blockedBoundary;
           var parentHoistableState = task.hoistableState,
             parentSegment = task.blockedSegment;
-          JSCompiler_inline_result = props.fallback;
+          propName = props.fallback;
           var content = props.children;
           props = new Set();
-          contextType$jscomp$0 = createSuspenseBoundary(request, props);
+          contextType = createSuspenseBoundary(request, props);
           null !== request.trackedPostpones &&
-            (contextType$jscomp$0.trackedContentKeyPath = keyPath);
+            (contextType.trackedContentKeyPath = keyPath);
           partial = createPendingSegment(
             request,
             parentSegment.chunks.length,
-            contextType$jscomp$0,
+            contextType,
             task.formatContext,
             !1,
             !1
@@ -3889,8 +3891,8 @@ function renderElement(request, task, keyPath, type, props, ref) {
             !1
           );
           contentRootSegment.parentFlushed = !0;
-          task.blockedBoundary = contextType$jscomp$0;
-          task.hoistableState = contextType$jscomp$0.contentState;
+          task.blockedBoundary = contextType;
+          task.hoistableState = contextType.contentState;
           task.blockedSegment = contentRootSegment;
           task.keyPath = keyPath;
           try {
@@ -3900,21 +3902,27 @@ function renderElement(request, task, keyPath, type, props, ref) {
                 contentRootSegment.textEmbedded &&
                 contentRootSegment.chunks.push("\x3c!-- --\x3e"),
               (contentRootSegment.status = 1),
-              queueCompletedSegment(contextType$jscomp$0, contentRootSegment),
-              0 === contextType$jscomp$0.pendingTasks &&
-                0 === contextType$jscomp$0.status)
+              queueCompletedSegment(contextType, contentRootSegment),
+              0 === contextType.pendingTasks && 0 === contextType.status)
             ) {
-              contextType$jscomp$0.status = 1;
+              contextType.status = 1;
               task.componentStack = previousComponentStack;
               break a;
             }
           } catch (error) {
             (contentRootSegment.status = 4),
-              (contextType$jscomp$0.status = 4),
-              (contextType = getThrownInfo(request, task.componentStack)),
-              (initialState = logRecoverableError(request, error, contextType)),
-              (contextType$jscomp$0.errorDigest = initialState),
-              untrackBoundary(request, contextType$jscomp$0);
+              (contextType.status = 4),
+              (JSCompiler_inline_result = getThrownInfo(
+                request,
+                task.componentStack
+              )),
+              (defaultProps = logRecoverableError(
+                request,
+                error,
+                JSCompiler_inline_result
+              )),
+              (contextType.errorDigest = defaultProps),
+              untrackBoundary(request, contextType);
           } finally {
             (task.blockedBoundary = ref),
               (task.hoistableState = parentHoistableState),
@@ -3922,31 +3930,37 @@ function renderElement(request, task, keyPath, type, props, ref) {
               (task.keyPath = prevKeyPath),
               (task.componentStack = previousComponentStack);
           }
-          contextType = [keyPath[0], "Suspense Fallback", keyPath[2]];
-          initialState = request.trackedPostpones;
-          null !== initialState &&
+          JSCompiler_inline_result = [
+            keyPath[0],
+            "Suspense Fallback",
+            keyPath[2]
+          ];
+          defaultProps = request.trackedPostpones;
+          null !== defaultProps &&
             ((previousComponentStack = [
-              contextType[1],
-              contextType[2],
+              JSCompiler_inline_result[1],
+              JSCompiler_inline_result[2],
               [],
               null
             ]),
-            initialState.workingMap.set(contextType, previousComponentStack),
-            5 === contextType$jscomp$0.status
-              ? (initialState.workingMap.get(keyPath)[4] =
+            defaultProps.workingMap.set(
+              JSCompiler_inline_result,
+              previousComponentStack
+            ),
+            5 === contextType.status
+              ? (defaultProps.workingMap.get(keyPath)[4] =
                   previousComponentStack)
-              : (contextType$jscomp$0.trackedFallbackNode =
-                  previousComponentStack));
+              : (contextType.trackedFallbackNode = previousComponentStack));
           task = createRenderTask(
             request,
             null,
-            JSCompiler_inline_result,
+            propName,
             -1,
             ref,
             partial,
-            contextType$jscomp$0.fallbackState,
+            contextType.fallbackState,
             props,
-            contextType,
+            JSCompiler_inline_result,
             task.formatContext,
             task.legacyContext,
             task.context,
@@ -3961,24 +3975,23 @@ function renderElement(request, task, keyPath, type, props, ref) {
     if ("object" === typeof type && null !== type)
       switch (type.$$typeof) {
         case REACT_FORWARD_REF_TYPE:
-          contextType = task.componentStack;
+          JSCompiler_inline_result = task.componentStack;
           task.componentStack = {
             tag: 1,
             parent: task.componentStack,
             type: type.render
           };
           if (enableRefAsProp && "ref" in props)
-            for (JSCompiler_inline_result in ((initialState = {}), props))
-              "ref" !== JSCompiler_inline_result &&
-                (initialState[JSCompiler_inline_result] =
-                  props[JSCompiler_inline_result]);
-          else initialState = props;
+            for (contextType in ((defaultProps = {}), props))
+              "ref" !== contextType &&
+                (defaultProps[contextType] = props[contextType]);
+          else defaultProps = props;
           props = renderWithHooks(
             request,
             task,
             keyPath,
             type.render,
-            initialState,
+            defaultProps,
             ref
           );
           finishFunctionComponent(
@@ -3990,11 +4003,11 @@ function renderElement(request, task, keyPath, type, props, ref) {
             actionStateCounter,
             actionStateMatchingIndex
           );
-          task.componentStack = contextType;
+          task.componentStack = JSCompiler_inline_result;
           return;
         case REACT_MEMO_TYPE:
           type = type.type;
-          props = resolveDefaultProps(type, props);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, ref);
           return;
         case REACT_PROVIDER_TYPE:
@@ -4013,13 +4026,13 @@ function renderElement(request, task, keyPath, type, props, ref) {
             return;
           }
         case REACT_LAZY_TYPE:
-          ref = task.componentStack;
+          JSCompiler_inline_result = task.componentStack;
           task.componentStack = createBuiltInComponentStack(task, "Lazy");
-          JSCompiler_inline_result = type._init;
-          type = JSCompiler_inline_result(type._payload);
-          props = resolveDefaultProps(type, props);
+          defaultProps = type._init;
+          type = defaultProps(type._payload);
+          props = resolveDefaultPropsOnNonClassComponent(type, props);
           renderElement(request, task, keyPath, type, props, void 0);
-          task.componentStack = ref;
+          task.componentStack = JSCompiler_inline_result;
           return;
       }
     throw Error(
diff --git a/compiled/facebook-www/ReactDOMTesting-dev.classic.js b/compiled/facebook-www/ReactDOMTesting-dev.classic.js
index b74e43652a..bd00fa7653 100644
--- a/compiled/facebook-www/ReactDOMTesting-dev.classic.js
+++ b/compiled/facebook-www/ReactDOMTesting-dev.classic.js
@@ -141,7 +141,9 @@ if (__DEV__) {
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
       enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
       favorSafetyOverHydrationPerf =
-        dynamicFeatureFlags.favorSafetyOverHydrationPerf; // On WWW, false is used for a new modern build.
+        dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -19285,7 +19287,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -19309,10 +19315,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -20474,7 +20483,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -20500,18 +20510,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -21741,7 +21754,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -21763,7 +21778,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -21780,14 +21797,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -21886,7 +21910,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -23890,9 +23917,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -23953,9 +23984,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -23985,9 +24017,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -33924,9 +33963,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           {
@@ -33958,9 +34001,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -36837,7 +36884,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-classic-06a8599f";
+    var ReactVersion = "19.0.0-www-classic-67c522ab";
 
     function createPortal$1(
       children,
diff --git a/compiled/facebook-www/ReactDOMTesting-dev.modern.js b/compiled/facebook-www/ReactDOMTesting-dev.modern.js
index 563e79ddee..6c2ad202a5 100644
--- a/compiled/facebook-www/ReactDOMTesting-dev.modern.js
+++ b/compiled/facebook-www/ReactDOMTesting-dev.modern.js
@@ -156,7 +156,9 @@ if (__DEV__) {
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
       enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
       favorSafetyOverHydrationPerf =
-        dynamicFeatureFlags.favorSafetyOverHydrationPerf; // On WWW, true is used for a new modern build.
+        dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
     var enableProfilerTimer = true;
     var enableProfilerCommitHooks = true;
     var enableProfilerNestedUpdatePhase = true;
@@ -29577,7 +29579,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -29601,10 +29607,13 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+      if (disableDefaultPropsExceptForClasses) {
+        // Support for defaultProps is removed in React 19 for all types
+        // except classes.
+        return baseProps;
+      }
+
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -30631,7 +30640,8 @@ if (__DEV__) {
         if (
           isSimpleFunctionComponent(type) &&
           Component.compare === null && // SimpleMemoComponent codepath doesn't resolve outer props either.
-          Component.defaultProps === undefined
+          (disableDefaultPropsExceptForClasses ||
+            Component.defaultProps === undefined)
         ) {
           var resolvedType = type;
 
@@ -30657,18 +30667,21 @@ if (__DEV__) {
           );
         }
 
-        {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+        if (!disableDefaultPropsExceptForClasses) {
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -31836,7 +31849,9 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = FunctionComponent;
 
@@ -31858,7 +31873,9 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = ForwardRef;
 
@@ -31875,14 +31892,21 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = disableDefaultPropsExceptForClasses
+            ? props
+            : resolveDefaultPropsOnNonClassComponent(Component, props);
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            disableDefaultPropsExceptForClasses
+              ? _resolvedProps3
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component.type,
+                  _resolvedProps3
+                ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -31945,7 +31969,10 @@ if (__DEV__) {
           }
         }
 
-        if (Component.defaultProps !== undefined) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          Component.defaultProps !== undefined
+        ) {
           var _componentName = getComponentNameFromType(Component) || "Unknown";
 
           if (!didWarnAboutDefaultPropsOnFunctionComponent[_componentName]) {
@@ -33859,9 +33886,13 @@ if (__DEV__) {
           var Component = workInProgress.type;
           var unresolvedProps = workInProgress.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -33922,9 +33953,10 @@ if (__DEV__) {
           var _unresolvedProps2 = workInProgress.pendingProps;
 
           var _resolvedProps5 =
+            disableDefaultPropsExceptForClasses ||
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -33954,9 +33986,16 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _unresolvedProps3
+            : resolveDefaultPropsOnNonClassComponent(_type, _unresolvedProps3);
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = disableDefaultPropsExceptForClasses
+            ? _resolvedProps6
+            : resolveDefaultPropsOnNonClassComponent(
+                _type.type,
+                _resolvedProps6
+              );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -43658,9 +43697,13 @@ if (__DEV__) {
           var Component = unitOfWork.type;
           var unresolvedProps = unitOfWork.pendingProps;
           var resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           next = replayFunctionComponent(
@@ -43683,9 +43726,13 @@ if (__DEV__) {
           var _unresolvedProps = unitOfWork.pendingProps;
 
           var _resolvedProps =
+            disableDefaultPropsExceptForClasses ||
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -46463,7 +46510,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-modern-2bc2ffbc";
+    var ReactVersion = "19.0.0-www-modern-77631c63";
 
     function createPortal$1(
       children,
diff --git a/compiled/facebook-www/ReactDOMTesting-prod.classic.js b/compiled/facebook-www/ReactDOMTesting-prod.classic.js
index 327b4f6239..f94eef3e3c 100644
--- a/compiled/facebook-www/ReactDOMTesting-prod.classic.js
+++ b/compiled/facebook-www/ReactDOMTesting-prod.classic.js
@@ -62,6 +62,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -4889,7 +4891,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -4901,7 +4906,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -5433,7 +5439,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -6742,7 +6748,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -6757,7 +6765,9 @@ function beginWork(current, workInProgress, renderLanes) {
               ((elementType = current.$$typeof),
               elementType === REACT_FORWARD_REF_TYPE)
             ) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -6768,13 +6778,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (elementType === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -6788,9 +6802,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -7042,9 +7057,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (elementType = workInProgress.pendingProps),
         (elementType =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? elementType
-            : resolveDefaultProps(props, elementType)),
+            : resolveDefaultPropsOnNonClassComponent(props, elementType)),
         updateForwardRef(
           current,
           workInProgress,
@@ -7131,8 +7147,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (elementType = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (elementType = resolveDefaultProps(props.type, elementType)),
+        (elementType = workInProgress.pendingProps),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props, elementType)),
+        (elementType = disableDefaultPropsExceptForClasses
+          ? elementType
+          : resolveDefaultPropsOnNonClassComponent(props.type, elementType)),
         updateMemoComponent(
           current,
           workInProgress,
@@ -11774,9 +11795,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       var context = isContextProvider(Component)
         ? previousContext
         : contextStackCursor.current;
@@ -11794,9 +11816,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -17322,7 +17345,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1731 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-classic-c508353a",
+  version: "19.0.0-www-classic-5ab1fc58",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2142 = {
@@ -17352,7 +17375,7 @@ var internals$jscomp$inline_2142 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-classic-c508353a"
+  reconcilerVersion: "19.0.0-www-classic-5ab1fc58"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2143 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -17951,4 +17974,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-classic-c508353a";
+exports.version = "19.0.0-www-classic-5ab1fc58";
diff --git a/compiled/facebook-www/ReactDOMTesting-prod.modern.js b/compiled/facebook-www/ReactDOMTesting-prod.modern.js
index 1d4f166727..72ca10c0b7 100644
--- a/compiled/facebook-www/ReactDOMTesting-prod.modern.js
+++ b/compiled/facebook-www/ReactDOMTesting-prod.modern.js
@@ -78,6 +78,8 @@ var ReactSharedInternals =
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
   favorSafetyOverHydrationPerf =
     dynamicFeatureFlags.favorSafetyOverHydrationPerf,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   REACT_ELEMENT_TYPE = Symbol.for("react.element"),
   REACT_PORTAL_TYPE = Symbol.for("react.portal"),
   REACT_FRAGMENT_TYPE = Symbol.for("react.fragment"),
@@ -8558,7 +8560,10 @@ function resolveClassComponentProps(
   alreadyResolvedDefaultProps
 ) {
   var newProps = baseProps;
-  if ((Component = Component.defaultProps) && !alreadyResolvedDefaultProps) {
+  if (
+    (Component = Component.defaultProps) &&
+    (disableDefaultPropsExceptForClasses || !alreadyResolvedDefaultProps)
+  ) {
     newProps = assign({}, newProps, baseProps);
     for (var propName in Component)
       void 0 === newProps[propName] &&
@@ -8570,7 +8575,8 @@ function resolveClassComponentProps(
     delete newProps.ref);
   return newProps;
 }
-function resolveDefaultProps(Component, baseProps) {
+function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
+  if (disableDefaultPropsExceptForClasses) return baseProps;
   if (Component && Component.defaultProps) {
     baseProps = assign({}, baseProps);
     Component = Component.defaultProps;
@@ -9005,7 +9011,7 @@ function updateMemoComponent(
       !shouldConstruct(type) &&
       void 0 === type.defaultProps &&
       null === Component.compare &&
-      void 0 === Component.defaultProps
+      (disableDefaultPropsExceptForClasses || void 0 === Component.defaultProps)
     )
       return (
         (workInProgress.tag = 15),
@@ -10275,7 +10281,9 @@ function beginWork(current, workInProgress, renderLanes) {
                 props,
                 renderLanes
               )))
-            : ((props = resolveDefaultProps(current, props)),
+            : ((props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props)),
               (workInProgress.tag = 0),
               (workInProgress = updateFunctionComponent(
                 null,
@@ -10287,7 +10295,9 @@ function beginWork(current, workInProgress, renderLanes) {
         else {
           if (void 0 !== current && null !== current)
             if (((init = current.$$typeof), init === REACT_FORWARD_REF_TYPE)) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 11;
               workInProgress = updateForwardRef(
                 null,
@@ -10298,13 +10308,17 @@ function beginWork(current, workInProgress, renderLanes) {
               );
               break a;
             } else if (init === REACT_MEMO_TYPE) {
-              props = resolveDefaultProps(current, props);
+              props = disableDefaultPropsExceptForClasses
+                ? props
+                : resolveDefaultPropsOnNonClassComponent(current, props);
               workInProgress.tag = 14;
               workInProgress = updateMemoComponent(
                 null,
                 workInProgress,
                 current,
-                resolveDefaultProps(current.type, props),
+                disableDefaultPropsExceptForClasses
+                  ? props
+                  : resolveDefaultPropsOnNonClassComponent(current.type, props),
                 renderLanes
               );
               break a;
@@ -10318,9 +10332,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateFunctionComponent(
           current,
           workInProgress,
@@ -10569,9 +10584,10 @@ function beginWork(current, workInProgress, renderLanes) {
         (props = workInProgress.type),
         (init = workInProgress.pendingProps),
         (init =
+          disableDefaultPropsExceptForClasses ||
           workInProgress.elementType === props
             ? init
-            : resolveDefaultProps(props, init)),
+            : resolveDefaultPropsOnNonClassComponent(props, init)),
         updateForwardRef(current, workInProgress, props, init, renderLanes)
       );
     case 7:
@@ -10644,8 +10660,13 @@ function beginWork(current, workInProgress, renderLanes) {
     case 14:
       return (
         (props = workInProgress.type),
-        (init = resolveDefaultProps(props, workInProgress.pendingProps)),
-        (init = resolveDefaultProps(props.type, init)),
+        (init = workInProgress.pendingProps),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props, init)),
+        (init = disableDefaultPropsExceptForClasses
+          ? init
+          : resolveDefaultPropsOnNonClassComponent(props.type, init)),
         updateMemoComponent(current, workInProgress, props, init, renderLanes)
       );
     case 15:
@@ -15174,9 +15195,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       var Component = unitOfWork.type,
         unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -15190,9 +15212,10 @@ function replaySuspendedUnitOfWork(unitOfWork) {
       Component = unitOfWork.type.render;
       unresolvedProps = unitOfWork.pendingProps;
       unresolvedProps =
+        disableDefaultPropsExceptForClasses ||
         unitOfWork.elementType === Component
           ? unresolvedProps
-          : resolveDefaultProps(Component, unresolvedProps);
+          : resolveDefaultPropsOnNonClassComponent(Component, unresolvedProps);
       current = replayFunctionComponent(
         current,
         unitOfWork,
@@ -16756,7 +16779,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1714 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "19.0.0-www-modern-4326b2be",
+  version: "19.0.0-www-modern-9e5a00ad",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2118 = {
@@ -16786,7 +16809,7 @@ var internals$jscomp$inline_2118 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "19.0.0-www-modern-4326b2be"
+  reconcilerVersion: "19.0.0-www-modern-9e5a00ad"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2119 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -17212,4 +17235,4 @@ exports.useFormState = function (action, initialState, permalink) {
 exports.useFormStatus = function () {
   return ReactCurrentDispatcher$2.current.useHostTransitionStatus();
 };
-exports.version = "19.0.0-www-modern-4326b2be";
+exports.version = "19.0.0-www-modern-9e5a00ad";
diff --git a/compiled/facebook-www/ReactServer-dev.modern.js b/compiled/facebook-www/ReactServer-dev.modern.js
index 2617eddbb0..7abccdb69f 100644
--- a/compiled/facebook-www/ReactServer-dev.modern.js
+++ b/compiled/facebook-www/ReactServer-dev.modern.js
@@ -85,8 +85,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
 
     /**
      * Keeps track of the current Cache dispatcher.
@@ -1349,14 +1350,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
@@ -1616,7 +1620,11 @@ if (__DEV__) {
 
         var defaultProps;
 
-        if (element.type && element.type.defaultProps) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          element.type &&
+          element.type.defaultProps
+        ) {
           defaultProps = element.type.defaultProps;
         }
 
@@ -1636,7 +1644,11 @@ if (__DEV__) {
             // backwards compatibility.
             !(enableRefAsProp && propName === "ref" && config.ref === undefined)
           ) {
-            if (config[propName] === undefined && defaultProps !== undefined) {
+            if (
+              !disableDefaultPropsExceptForClasses &&
+              config[propName] === undefined &&
+              defaultProps !== undefined
+            ) {
               // Resolve default props
               props[propName] = defaultProps[propName];
             } else {
@@ -2510,55 +2522,35 @@ if (__DEV__) {
         _init: lazyInitializer
       };
 
-      {
-        // In production, this would just set it on the object.
-        var defaultProps;
-        var propTypes; // $FlowFixMe[prop-missing]
+      if (!disableDefaultPropsExceptForClasses) {
+        {
+          // In production, this would just set it on the object.
+          var defaultProps; // $FlowFixMe[prop-missing]
 
-        Object.defineProperties(lazyType, {
-          defaultProps: {
-            configurable: true,
-            get: function () {
-              return defaultProps;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newDefaultProps) {
-              error(
-                "It is not supported to assign `defaultProps` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
+          Object.defineProperties(lazyType, {
+            defaultProps: {
+              configurable: true,
+              get: function () {
+                return defaultProps;
+              },
+              // $FlowFixMe[missing-local-annot]
+              set: function (newDefaultProps) {
+                error(
+                  "It is not supported to assign `defaultProps` to " +
+                    "a lazy component import. Either specify them where the component " +
+                    "is defined, or create a wrapping component around it."
+                );
 
-              defaultProps = newDefaultProps; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+                defaultProps = newDefaultProps; // Match production behavior more closely:
+                // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "defaultProps", {
-                enumerable: true
-              });
+                Object.defineProperty(lazyType, "defaultProps", {
+                  enumerable: true
+                });
+              }
             }
-          },
-          propTypes: {
-            configurable: true,
-            get: function () {
-              return propTypes;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newPropTypes) {
-              error(
-                "It is not supported to assign `propTypes` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
-
-              propTypes = newPropTypes; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
-
-              Object.defineProperty(lazyType, "propTypes", {
-                enumerable: true
-              });
-            }
-          }
-        });
+          });
+        }
       }
 
       return lazyType;
@@ -2832,7 +2824,7 @@ if (__DEV__) {
 
     function noop() {}
 
-    var ReactVersion = "19.0.0-www-modern-aac4a3b6";
+    var ReactVersion = "19.0.0-www-modern-1ec419e8";
 
     // Patch fetch
     var Children = {
diff --git a/compiled/facebook-www/ReactServer-prod.modern.js b/compiled/facebook-www/ReactServer-prod.modern.js
index b57542cd9a..c371c8b74e 100644
--- a/compiled/facebook-www/ReactServer-prod.modern.js
+++ b/compiled/facebook-www/ReactServer-prod.modern.js
@@ -15,6 +15,8 @@ var assign = Object.assign,
   dynamicFeatureFlags = require("ReactFeatureFlags"),
   enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
   enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+  disableDefaultPropsExceptForClasses =
+    dynamicFeatureFlags.disableDefaultPropsExceptForClasses,
   ReactCurrentCache = { current: null },
   ReactCurrentDispatcher = { current: null },
   ReactSharedInternals = {
@@ -82,7 +84,7 @@ function jsxProd(type, config, maybeKey) {
       "key" !== propName &&
       (enableRefAsProp || "ref" !== propName) &&
       (props[propName] = config[propName]);
-  if (type && type.defaultProps)
+  if (!disableDefaultPropsExceptForClasses && type && type.defaultProps)
     for (propName in ((config = type.defaultProps), config))
       void 0 === props[propName] && (props[propName] = config[propName]);
   return ReactElement(
@@ -425,7 +427,11 @@ exports.cloneElement = function (element, config, children) {
       (enableRefAsProp || (ref = config.ref),
       (owner = ReactCurrentOwner.current));
     void 0 !== config.key && (key = "" + config.key);
-    if (element.type && element.type.defaultProps)
+    if (
+      !disableDefaultPropsExceptForClasses &&
+      element.type &&
+      element.type.defaultProps
+    )
       var defaultProps = element.type.defaultProps;
     for (propName in config)
       !hasOwnProperty.call(config, propName) ||
@@ -435,9 +441,11 @@ exports.cloneElement = function (element, config, children) {
         "__source" === propName ||
         (enableRefAsProp && "ref" === propName && void 0 === config.ref) ||
         (props[propName] =
-          void 0 === config[propName] && void 0 !== defaultProps
-            ? defaultProps[propName]
-            : config[propName]);
+          disableDefaultPropsExceptForClasses ||
+          void 0 !== config[propName] ||
+          void 0 === defaultProps
+            ? config[propName]
+            : defaultProps[propName]);
   }
   var propName = arguments.length - 2;
   if (1 === propName) props.children = children;
@@ -555,4 +563,4 @@ exports.useId = function () {
 exports.useMemo = function (create, deps) {
   return ReactCurrentDispatcher.current.useMemo(create, deps);
 };
-exports.version = "19.0.0-www-modern-342eadac";
+exports.version = "19.0.0-www-modern-53e0c063";
diff --git a/compiled/facebook-www/ReactTestRenderer-dev.classic.js b/compiled/facebook-www/ReactTestRenderer-dev.classic.js
index ee85a90649..05db70fc34 100644
--- a/compiled/facebook-www/ReactTestRenderer-dev.classic.js
+++ b/compiled/facebook-www/ReactTestRenderer-dev.classic.js
@@ -13129,7 +13129,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        !alreadyResolvedDefaultProps
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -13142,10 +13146,7 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -13988,17 +13989,20 @@ if (__DEV__) {
         }
 
         {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -14942,7 +14946,10 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = FunctionComponent;
 
@@ -14964,7 +14971,10 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = ForwardRef;
 
@@ -14981,14 +14991,20 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            resolveDefaultPropsOnNonClassComponent(
+              Component.type,
+              _resolvedProps3
+            ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -16827,7 +16843,10 @@ if (__DEV__) {
           var resolvedProps =
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -16886,7 +16905,7 @@ if (__DEV__) {
           var _resolvedProps5 =
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -16916,9 +16935,15 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = resolveDefaultPropsOnNonClassComponent(
+            _type,
+            _unresolvedProps3
+          );
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = resolveDefaultPropsOnNonClassComponent(
+            _type.type,
+            _resolvedProps6
+          );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -24310,7 +24335,10 @@ if (__DEV__) {
           var resolvedProps =
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           {
@@ -24344,7 +24372,10 @@ if (__DEV__) {
           var _resolvedProps =
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -26827,7 +26858,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-classic-272ef63e";
+    var ReactVersion = "19.0.0-www-classic-74b383db";
 
     // Might add PROFILE later.
 
diff --git a/compiled/facebook-www/ReactTestRenderer-dev.modern.js b/compiled/facebook-www/ReactTestRenderer-dev.modern.js
index fdd4aed6d4..197a64e17e 100644
--- a/compiled/facebook-www/ReactTestRenderer-dev.modern.js
+++ b/compiled/facebook-www/ReactTestRenderer-dev.modern.js
@@ -13129,7 +13129,11 @@ if (__DEV__) {
 
       var defaultProps = Component.defaultProps;
 
-      if (defaultProps && !alreadyResolvedDefaultProps) {
+      if (
+        defaultProps && // If disableDefaultPropsExceptForClasses is true, we always resolve
+        // default props here in the reconciler, rather than in the JSX runtime.
+        !alreadyResolvedDefaultProps
+      ) {
         newProps = assign({}, newProps, baseProps);
 
         for (var propName in defaultProps) {
@@ -13142,10 +13146,7 @@ if (__DEV__) {
       return newProps;
     }
 
-    function resolveDefaultProps(Component, baseProps) {
-      // TODO: Remove support for default props for everything except class
-      // components, including setting default props on a lazy wrapper around a
-      // class type.
+    function resolveDefaultPropsOnNonClassComponent(Component, baseProps) {
       if (Component && Component.defaultProps) {
         // Resolve default props. Taken from ReactElement
         var props = assign({}, baseProps);
@@ -13988,17 +13989,20 @@ if (__DEV__) {
         }
 
         {
-          if (Component.defaultProps !== undefined) {
-            var componentName = getComponentNameFromType(type) || "Unknown";
+          {
+            if (Component.defaultProps !== undefined) {
+              var componentName = getComponentNameFromType(type) || "Unknown";
 
-            if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
-              error(
-                "%s: Support for defaultProps will be removed from memo components " +
-                  "in a future major release. Use JavaScript default parameters instead.",
-                componentName
-              );
+              if (!didWarnAboutDefaultPropsOnFunctionComponent[componentName]) {
+                error(
+                  "%s: Support for defaultProps will be removed from memo components " +
+                    "in a future major release. Use JavaScript default parameters instead.",
+                  componentName
+                );
 
-              didWarnAboutDefaultPropsOnFunctionComponent[componentName] = true;
+                didWarnAboutDefaultPropsOnFunctionComponent[componentName] =
+                  true;
+              }
             }
           }
         }
@@ -14942,7 +14946,10 @@ if (__DEV__) {
             renderLanes
           );
         } else {
-          var _resolvedProps = resolveDefaultProps(Component, props);
+          var _resolvedProps = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = FunctionComponent;
 
@@ -14964,7 +14971,10 @@ if (__DEV__) {
         var $$typeof = Component.$$typeof;
 
         if ($$typeof === REACT_FORWARD_REF_TYPE) {
-          var _resolvedProps2 = resolveDefaultProps(Component, props);
+          var _resolvedProps2 = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = ForwardRef;
 
@@ -14981,14 +14991,20 @@ if (__DEV__) {
             renderLanes
           );
         } else if ($$typeof === REACT_MEMO_TYPE) {
-          var _resolvedProps3 = resolveDefaultProps(Component, props);
+          var _resolvedProps3 = resolveDefaultPropsOnNonClassComponent(
+            Component,
+            props
+          );
 
           workInProgress.tag = MemoComponent;
           return updateMemoComponent(
             null,
             workInProgress,
             Component,
-            resolveDefaultProps(Component.type, _resolvedProps3), // The inner type can have defaults too
+            resolveDefaultPropsOnNonClassComponent(
+              Component.type,
+              _resolvedProps3
+            ), // The inner type can have defaults too
             renderLanes
           );
         }
@@ -16827,7 +16843,10 @@ if (__DEV__) {
           var resolvedProps =
             workInProgress.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           return updateFunctionComponent(
             current,
             workInProgress,
@@ -16886,7 +16905,7 @@ if (__DEV__) {
           var _resolvedProps5 =
             workInProgress.elementType === type
               ? _unresolvedProps2
-              : resolveDefaultProps(type, _unresolvedProps2);
+              : resolveDefaultPropsOnNonClassComponent(type, _unresolvedProps2);
 
           return updateForwardRef(
             current,
@@ -16916,9 +16935,15 @@ if (__DEV__) {
           var _type = workInProgress.type;
           var _unresolvedProps3 = workInProgress.pendingProps; // Resolve outer props first, then resolve inner props.
 
-          var _resolvedProps6 = resolveDefaultProps(_type, _unresolvedProps3);
+          var _resolvedProps6 = resolveDefaultPropsOnNonClassComponent(
+            _type,
+            _unresolvedProps3
+          );
 
-          _resolvedProps6 = resolveDefaultProps(_type.type, _resolvedProps6);
+          _resolvedProps6 = resolveDefaultPropsOnNonClassComponent(
+            _type.type,
+            _resolvedProps6
+          );
           return updateMemoComponent(
             current,
             workInProgress,
@@ -24310,7 +24335,10 @@ if (__DEV__) {
           var resolvedProps =
             unitOfWork.elementType === Component
               ? unresolvedProps
-              : resolveDefaultProps(Component, unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  Component,
+                  unresolvedProps
+                );
           var context;
 
           {
@@ -24344,7 +24372,10 @@ if (__DEV__) {
           var _resolvedProps =
             unitOfWork.elementType === _Component
               ? _unresolvedProps
-              : resolveDefaultProps(_Component, _unresolvedProps);
+              : resolveDefaultPropsOnNonClassComponent(
+                  _Component,
+                  _unresolvedProps
+                );
 
           next = replayFunctionComponent(
             current,
@@ -26827,7 +26858,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-modern-272ef63e";
+    var ReactVersion = "19.0.0-www-modern-74b383db";
 
     // Might add PROFILE later.
 
diff --git a/compiled/facebook-www/__test_utils__/ReactAllWarnings.js b/compiled/facebook-www/__test_utils__/ReactAllWarnings.js
index 6e81ad525e..2f37fd1ce2 100644
--- a/compiled/facebook-www/__test_utils__/ReactAllWarnings.js
+++ b/compiled/facebook-www/__test_utils__/ReactAllWarnings.js
@@ -188,7 +188,6 @@ export default [
   "Invalid value for prop %s on <%s> tag. Either remove it from the element, or pass a string or number value to keep it in the DOM. For details, see https://react.dev/link/attribute-behavior ",
   "Invalid values for props %s on <%s> tag. Either remove them from the element, or pass a string or number value to keep them in the DOM. For details, see https://react.dev/link/attribute-behavior ",
   "It is not supported to assign `defaultProps` to a lazy component import. Either specify them where the component is defined, or create a wrapping component around it.",
-  "It is not supported to assign `propTypes` to a lazy component import. Either specify them where the component is defined, or create a wrapping component around it.",
   "It looks like %s is reassigning its own `this.props` while rendering. This is not supported and can lead to confusing bugs.",
   "It looks like the React-rendered content of this container was removed without using React. This is not supported and will cause errors. Instead, call ReactDOM.unmountComponentAtNode to empty a container.",
   "Legacy context API has been detected within a strict-mode tree.\n\nThe old API will be supported in all 16.x releases, but applications using it should migrate to the new version.\n\nPlease update the following components: %s\n\nLearn more about this warning here: https://react.dev/link/legacy-context",