diff --git a/packages/react-dom/src/__tests__/ReactDOM-test.js b/packages/react-dom/src/__tests__/ReactDOM-test.js
index 8c21143d52d72..0b9e9ce44c05e 100644
--- a/packages/react-dom/src/__tests__/ReactDOM-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOM-test.js
@@ -434,10 +434,10 @@ describe('ReactDOM', () => {
     }
   });
 
-  it('warns when requestAnimationFrame is not polyfilled in the browser', () => {
+  it('warns when requestAnimationFrame is not polyfilled', () => {
     const previousRAF = global.requestAnimationFrame;
     try {
-      global.requestAnimationFrame = undefined;
+      delete global.requestAnimationFrame;
       jest.resetModules();
       expect(() => require('react-dom')).toWarnDev(
         "This browser doesn't support requestAnimationFrame.",
diff --git a/packages/react-scheduler/src/ReactScheduler.js b/packages/react-scheduler/src/ReactScheduler.js
index 50252a827ab8e..e59176411d2e4 100644
--- a/packages/react-scheduler/src/ReactScheduler.js
+++ b/packages/react-scheduler/src/ReactScheduler.js
@@ -44,18 +44,6 @@ export type CallbackIdType = CallbackConfigType;
 import {canUseDOM} from 'shared/ExecutionEnvironment';
 import warning from 'shared/warning';
 
-if (__DEV__) {
-  if (canUseDOM && typeof requestAnimationFrame !== 'function') {
-    warning(
-      false,
-      // TODO: reword this when schedule is a stand-alone module
-      "This browser doesn't support requestAnimationFrame. " +
-        'Make sure that you load a ' +
-        'polyfill in older browsers. https://fb.me/react-polyfills',
-    );
-  }
-}
-
 // We capture a local reference to any global, in case it gets polyfilled after
 // this module is initially evaluated.
 // We want to be using a consistent implementation.
@@ -64,12 +52,24 @@ const localDate = Date;
 // This initialization code may run even on server environments
 // if a component just imports ReactDOM (e.g. for findDOMNode).
 // Some environments might not have setTimeout or clearTimeout.
+// However, we always expect them to be defined on the client.
 // https://github.com/facebook/react/pull/13088
 const localSetTimeout =
   typeof setTimeout === 'function' ? setTimeout : (undefined: any);
 const localClearTimeout =
   typeof clearTimeout === 'function' ? clearTimeout : (undefined: any);
 
+// We don't expect either of these to necessarily be defined,
+// but we will error later if they are missing on the client.
+const localRequestAnimationFrame =
+  typeof requestAnimationFrame === 'function'
+    ? requestAnimationFrame
+    : (undefined: any);
+const localCancelAnimationFrame =
+  typeof cancelAnimationFrame === 'function'
+    ? cancelAnimationFrame
+    : (undefined: any);
+
 const hasNativePerformanceNow =
   typeof performance === 'object' && typeof performance.now === 'function';
 
@@ -123,8 +123,22 @@ if (!canUseDOM) {
     localClearTimeout(timeoutId);
   };
 } else {
-  const localRequestAnimationFrame = requestAnimationFrame;
-  const localCancelAnimationFrame = cancelAnimationFrame;
+  if (typeof localRequestAnimationFrame !== 'function') {
+    warning(
+      false,
+      "This browser doesn't support requestAnimationFrame. " +
+        'Make sure that you load a ' +
+        'polyfill in older browsers. https://fb.me/react-polyfills',
+    );
+  }
+  if (typeof localCancelAnimationFrame !== 'function') {
+    warning(
+      false,
+      "This browser doesn't support cancelAnimationFrame. " +
+        'Make sure that you load a ' +
+        'polyfill in older browsers. https://fb.me/react-polyfills',
+    );
+  }
 
   let headOfPendingCallbacksLinkedList: CallbackConfigType | null = null;
   let tailOfPendingCallbacksLinkedList: CallbackConfigType | null = null;