diff --git a/js/modules/idle_detector.js b/js/modules/idle_detector.js
index 2404b304e..384074ace 100644
--- a/js/modules/idle_detector.js
+++ b/js/modules/idle_detector.js
@@ -29,7 +29,7 @@ class IdleDetector extends EventEmitter {
 
   _scheduleNextCallback() {
     this.stop();
-    this.handle = requestIdleCallback((deadline) => {
+    this.handle = window.requestIdleCallback((deadline) => {
       const { didTimeout } = deadline;
       const timeRemaining = deadline.timeRemaining();
       const isIdle = timeRemaining >= IDLE_THRESHOLD_MS;