diff --git a/mod/quiz/module.js b/mod/quiz/module.js
index <HASH>..<HASH> 100644
--- a/mod/quiz/module.js
+++ b/mod/quiz/module.js
@@ -219,8 +219,8 @@ M.mod_quiz.secure_window = {
             window.location = 'about:blank';
         }
         Y.delegate('contextmenu', M.mod_quiz.secure_window.prevent, document, '*');
-        Y.delegate('mousedown',   M.mod_quiz.secure_window.prevent_mouse, document, '*');
-        Y.delegate('mouseup',     M.mod_quiz.secure_window.prevent_mouse, document, '*');
+        Y.delegate('mousedown',   M.mod_quiz.secure_window.prevent_mouse, 'body', '*');
+        Y.delegate('mouseup',     M.mod_quiz.secure_window.prevent_mouse, 'body', '*');
         Y.delegate('dragstart',   M.mod_quiz.secure_window.prevent, document, '*');
         Y.delegate('selectstart', M.mod_quiz.secure_window.prevent, document, '*');
         Y.delegate('cut',         M.mod_quiz.secure_window.prevent, document, '*');
MDL-<I> mod_quiz: Scrollbar not working in Javascript Security Popup Quiz window in Chrome