diff --git a/.eslintrc.js b/.eslintrc.js
index 6dd119127ff47..715c6eb96074a 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -116,12 +116,7 @@ module.exports = {
     'react-internal/no-cross-fork-types': [
       ERROR,
       {
-        old: [
-          'firstEffect',
-          'nextEffect',
-          // Disabled because it's also used by the Hook type.
-          // 'lastEffect',
-        ],
+        old: [],
         new: [],
       },
     ],
@@ -190,7 +185,7 @@ module.exports = {
     {
       files: [
         'packages/react-native-renderer/**/*.js',
-        'packages/react-transport-native-relay/**/*.js'
+        'packages/react-transport-native-relay/**/*.js',
       ],
       globals: {
         nativeFabricUIManager: true,
diff --git a/packages/react-reconciler/src/ReactFiber.new.js b/packages/react-reconciler/src/ReactFiber.new.js
index 0dcff2f776fb4..ccad1371d8f40 100644
--- a/packages/react-reconciler/src/ReactFiber.new.js
+++ b/packages/react-reconciler/src/ReactFiber.new.js
@@ -141,6 +141,10 @@ function FiberNode(
 
   // Effects
   this.flags = NoFlags;
+  this.nextEffect = null;
+
+  this.firstEffect = null;
+  this.lastEffect = null;
   this.subtreeFlags = NoFlags;
   this.deletions = null;
 
@@ -805,6 +809,9 @@ export function assignFiberPropertiesInDEV(
   target.dependencies = source.dependencies;
   target.mode = source.mode;
   target.flags = source.flags;
+  target.nextEffect = source.nextEffect;
+  target.firstEffect = source.firstEffect;
+  target.lastEffect = source.lastEffect;
   target.subtreeFlags = source.subtreeFlags;
   target.deletions = source.deletions;
   target.lanes = source.lanes;