diff --git a/scripts/fiber/tests-failing.txt b/scripts/fiber/tests-failing.txt
index 36eaf9ae75..f6453126c2 100644
--- a/scripts/fiber/tests-failing.txt
+++ b/scripts/fiber/tests-failing.txt
@@ -34,7 +34,6 @@ src/renderers/dom/shared/__tests__/ReactDOMTextComponent-test.js
 * can reconcile text arbitrarily split into multiple nodes on some substitutions only
 
 src/renderers/dom/shared/__tests__/ReactMount-test.js
-* tracks root instances
 * marks top-level mounts
 
 src/renderers/dom/shared/__tests__/ReactRenderDocument-test.js
diff --git a/scripts/fiber/tests-passing.txt b/scripts/fiber/tests-passing.txt
index 072fe05988..1a468c2616 100644
--- a/scripts/fiber/tests-passing.txt
+++ b/scripts/fiber/tests-passing.txt
@@ -815,7 +815,6 @@ src/renderers/__tests__/ReactUpdates-test.js
 * should update children even if parent blocks updates
 * should not reconcile children passed via props
 * should flow updates correctly
-* should share reconcile transaction across different roots
 * should queue mount-ready handlers across different roots
 * should flush updates in the correct order
 * should flush updates in the correct order across roots
@@ -1071,14 +1070,13 @@ src/renderers/dom/shared/__tests__/ReactDOMComponent-test.js
 * gives source code refs for unknown prop warning for exact elements
 * gives source code refs for unknown prop warning for exact elements in composition
 * should suggest property name if available
+* renders innerHTML and preserves whitespace
+* render and then updates innerHTML and preserves whitespace
 
 src/renderers/dom/shared/__tests__/ReactDOMComponentTree-test.js
 * finds nodes for instances
 * finds instances for nodes
 
-src/renderers/dom/shared/__tests__/ReactDOMIDOperations-test.js
-* should update innerHTML and preserve whitespace
-
 src/renderers/dom/shared/__tests__/ReactDOMInvalidARIAHook-test.js
 * should allow valid aria-* props
 * should warn for one invalid aria-* prop
diff --git a/src/renderers/dom/shared/ReactDOMFeatureFlags.js b/src/renderers/dom/shared/ReactDOMFeatureFlags.js
index 17bae0a58a..5e9d93267c 100644
--- a/src/renderers/dom/shared/ReactDOMFeatureFlags.js
+++ b/src/renderers/dom/shared/ReactDOMFeatureFlags.js
@@ -13,7 +13,7 @@
 
 var ReactDOMFeatureFlags = {
   useCreateElement: true,
-  useFiber: true,
+  useFiber: false,
 };
 
 module.exports = ReactDOMFeatureFlags;