diff --git a/packages/react-reconciler/src/ReactFiberRoot.new.js b/packages/react-reconciler/src/ReactFiberRoot.new.js
index d69d2d77e5dfa..10047b1ac13c7 100644
--- a/packages/react-reconciler/src/ReactFiberRoot.new.js
+++ b/packages/react-reconciler/src/ReactFiberRoot.new.js
@@ -59,10 +59,6 @@ function FiberRootNode(containerInfo, tag, hydrate) {
     this.pooledCacheLanes = NoLanes;
   }
 
-  if (supportsHydration) {
-    this.mutableSourceEagerHydrationData = null;
-  }
-
   if (enableSuspenseCallback) {
     this.hydrationCallbacks = null;
   }
diff --git a/packages/react-reconciler/src/ReactFiberRoot.old.js b/packages/react-reconciler/src/ReactFiberRoot.old.js
index 8469d6c85b506..5e1768d932820 100644
--- a/packages/react-reconciler/src/ReactFiberRoot.old.js
+++ b/packages/react-reconciler/src/ReactFiberRoot.old.js
@@ -59,10 +59,6 @@ function FiberRootNode(containerInfo, tag, hydrate) {
     this.pooledCacheLanes = NoLanes;
   }
 
-  if (supportsHydration) {
-    this.mutableSourceEagerHydrationData = null;
-  }
-
   if (enableSuspenseCallback) {
     this.hydrationCallbacks = null;
   }