diff --git a/packages/priority-queue/src/request-idle-callback.js b/packages/priority-queue/src/request-idle-callback.js
index 3e81110600b127..eee8044fe365e5 100644
--- a/packages/priority-queue/src/request-idle-callback.js
+++ b/packages/priority-queue/src/request-idle-callback.js
@@ -2,7 +2,7 @@
  * @return {typeof window.requestIdleCallback|typeof window.requestAnimationFrame|((callback:(timestamp:number)=>void)=>void)}
  */
 export function createRequestIdleCallback() {
-	if ( typeof 'window' === undefined ) {
+	if ( typeof window === 'undefined' ) {
 		return ( callback ) => {
 			setTimeout( () => callback( Date.now() ), 0 );
 		};