diff --git a/content.js b/content.js
index a2b3b16aa91906a370015391fb75b393a0f8389d..b11a679e6b5dfd6a36003993738b616826cab9e0 100644
--- a/content.js
+++ b/content.js
@@ -104,9 +104,9 @@ let Content = {
     instructions: "This time the area on left does not have any visible content. However, this exercise defines a JavaScript function that can grant you points. Your task is to use the browser console to call the function like this: <code>giveMePoints();</code>",
     html: "<div id=\"events\"></div>",
     script: function giveMePoints() {
-      window.parent.postMessage('grade');
+      window.postMessage('grade');
     },
-    selector: "$window.parent",
+    selector: "$window",
     events: "message",
     points: function ($element, config, event) {
       if (event.originalEvent.data == 'grade') {