diff --git a/packages/react-reconciler/src/ReactFiberCache.js b/packages/react-reconciler/src/ReactFiberCache.js
index 08a1406904..379425fc22 100644
--- a/packages/react-reconciler/src/ReactFiberCache.js
+++ b/packages/react-reconciler/src/ReactFiberCache.js
@@ -7,13 +7,15 @@
  * @flow
  */
 
-import type {AsyncDispatcher} from './ReactInternalTypes';
+import type {AsyncDispatcher, Fiber} from './ReactInternalTypes';
 import type {Cache} from './ReactFiberCacheComponent';
 
 import {enableCache} from 'shared/ReactFeatureFlags';
 import {readContext} from './ReactFiberNewContext';
 import {CacheContext} from './ReactFiberCacheComponent';
 
+import {disableStringRefs} from 'shared/ReactFeatureFlags';
+
 function getCacheForType<T>(resourceType: () => T): T {
   if (!enableCache) {
     throw new Error('Not implemented.');
@@ -27,6 +29,13 @@ function getCacheForType<T>(resourceType: () => T): T {
   return cacheForType;
 }
 
-export const DefaultAsyncDispatcher: AsyncDispatcher = {
+export const DefaultAsyncDispatcher: AsyncDispatcher = ({
   getCacheForType,
-};
+}: any);
+
+if (__DEV__ || !disableStringRefs) {
+  DefaultAsyncDispatcher.getOwner = (): null | Fiber => {
+    // TODO
+    return null;
+  };
+}
diff --git a/packages/react-reconciler/src/ReactInternalTypes.js b/packages/react-reconciler/src/ReactInternalTypes.js
index db5078e3f5..6fa9142e2d 100644
--- a/packages/react-reconciler/src/ReactInternalTypes.js
+++ b/packages/react-reconciler/src/ReactInternalTypes.js
@@ -436,4 +436,6 @@ export type Dispatcher = {
 
 export type AsyncDispatcher = {
   getCacheForType: <T>(resourceType: () => T) => T,
+  // DEV-only (or !disableStringRefs)
+  getOwner: () => null | Fiber | ReactComponentInfo,
 };
diff --git a/packages/react-server/src/ReactFizzCache.js b/packages/react-server/src/ReactFizzCache.js
index c77b650e79..8e8cb2e219 100644
--- a/packages/react-server/src/ReactFizzCache.js
+++ b/packages/react-server/src/ReactFizzCache.js
@@ -9,10 +9,19 @@
 
 import type {AsyncDispatcher} from 'react-reconciler/src/ReactInternalTypes';
 
+import {disableStringRefs} from 'shared/ReactFeatureFlags';
+
 function getCacheForType<T>(resourceType: () => T): T {
   throw new Error('Not implemented.');
 }
 
-export const DefaultAsyncDispatcher: AsyncDispatcher = {
+export const DefaultAsyncDispatcher: AsyncDispatcher = ({
   getCacheForType,
-};
+}: any);
+
+if (__DEV__ || !disableStringRefs) {
+  // Fizz never tracks owner but the JSX runtime looks for this.
+  DefaultAsyncDispatcher.getOwner = (): null => {
+    return null;
+  };
+}
diff --git a/packages/react-server/src/flight/ReactFlightServerCache.js b/packages/react-server/src/flight/ReactFlightServerCache.js
index eefc5f9f3e..8ff0cd5bc9 100644
--- a/packages/react-server/src/flight/ReactFlightServerCache.js
+++ b/packages/react-server/src/flight/ReactFlightServerCache.js
@@ -7,10 +7,14 @@
  * @flow
  */
 
+import type {ReactComponentInfo} from 'shared/ReactTypes';
+
 import type {AsyncDispatcher} from 'react-reconciler/src/ReactInternalTypes';
 
 import {resolveRequest, getCache} from '../ReactFlightServer';
 
+import {disableStringRefs} from 'shared/ReactFeatureFlags';
+
 function resolveCache(): Map<Function, mixed> {
   const request = resolveRequest();
   if (request) {
@@ -19,7 +23,7 @@ function resolveCache(): Map<Function, mixed> {
   return new Map();
 }
 
-export const DefaultAsyncDispatcher: AsyncDispatcher = {
+export const DefaultAsyncDispatcher: AsyncDispatcher = ({
   getCacheForType<T>(resourceType: () => T): T {
     const cache = resolveCache();
     let entry: T | void = (cache.get(resourceType): any);
@@ -30,4 +34,16 @@ export const DefaultAsyncDispatcher: AsyncDispatcher = {
     }
     return entry;
   },
-};
+}: any);
+
+if (__DEV__) {
+  DefaultAsyncDispatcher.getOwner = (): null | ReactComponentInfo => {
+    // TODO
+    return null;
+  };
+} else if (!disableStringRefs) {
+  // Server Components never use string refs but the JSX runtime looks for it.
+  DefaultAsyncDispatcher.getOwner = (): null | ReactComponentInfo => {
+    return null;
+  };
+}
diff --git a/packages/react-suspense-test-utils/src/ReactSuspenseTestUtils.js b/packages/react-suspense-test-utils/src/ReactSuspenseTestUtils.js
index 35b59b61d1..bc2d4bee79 100644
--- a/packages/react-suspense-test-utils/src/ReactSuspenseTestUtils.js
+++ b/packages/react-suspense-test-utils/src/ReactSuspenseTestUtils.js
@@ -22,6 +22,9 @@ export function waitForSuspense<T>(fn: () => T): Promise<T> {
       }
       return entry;
     },
+    getOwner(): null {
+      return null;
+    },
   };
   // Not using async/await because we don't compile it.
   return new Promise((resolve, reject) => {