diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java
index 1b3cebc1f..bc68ab326 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ShadowNodeRegistry.java
@@ -28,9 +28,7 @@ public class ShadowNodeRegistry {
   }
 
   public void addRootNode(ReactShadowNode node) {
-    // TODO(6242243): This should be asserted... but UIManagerModule is
-    // thread-unsafe and calls this on the wrong thread.
-    //mThreadAsserter.assertNow();
+    mThreadAsserter.assertNow();
     int tag = node.getReactTag();
     mTagsToCSSNodes.put(tag, node);
     mRootTags.put(tag, true);
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
index 186a4d435..5f124ab88 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
@@ -205,7 +205,12 @@ public class UIImplementation {
     int heightMeasureSpec = rootView.getHeightMeasureSpec();
     updateRootView(rootCSSNode, widthMeasureSpec, heightMeasureSpec);
 
-    mShadowNodeRegistry.addRootNode(rootCSSNode);
+    context.runOnNativeModulesQueueThread(new Runnable() {
+      @Override
+      public void run() {
+        mShadowNodeRegistry.addRootNode(rootCSSNode);
+      }
+    });
 
     // register it within NativeViewHierarchyManager
     mOperationsQueue.addRootView(tag, rootView, context);