diff --git a/js/questionset.js b/js/questionset.js
index 13133fc..ae0442b 100644
--- a/js/questionset.js
+++ b/js/questionset.js
@@ -123,7 +123,7 @@ H5P.QuestionSet = function (options, contentId) {
         enableSolutionsButton: params.override.overrideShowSolutionButton
       });
     }
-    var questionInstance = H5P.newRunnable(question, contentId, null, null, self);
+    var questionInstance = H5P.newRunnable(question, contentId, undefined, undefined, {parent: self});
     questionInstances.push(questionInstance);
     questionInstance.on('resize', function() {
       self.trigger('resize');