diff --git a/dom/tests/mochitest/geolocation/geolocation_common.js b/dom/tests/mochitest/geolocation/geolocation_common.js
index c1f545848ae5..fc8018b1db79 100644
--- a/dom/tests/mochitest/geolocation/geolocation_common.js
+++ b/dom/tests/mochitest/geolocation/geolocation_common.js
@@ -73,7 +73,7 @@ function getChromeWindow()
 function getNotificationBox()
 {
   var chromeWin = getChromeWindow();
-  var notifyBox = chromeWin.getNotificationBox(chromeWin);
+  var notifyBox = chromeWin.getNotificationBox(window.top);
 
   return notifyBox;
 }