diff --git a/mod/quiz/addrandom.php b/mod/quiz/addrandom.php
index 9950735746d..c7f832cf2aa 100644
--- a/mod/quiz/addrandom.php
+++ b/mod/quiz/addrandom.php
@@ -96,6 +96,8 @@ if ($data = $mform->get_data()) {
     }
 
     quiz_add_random_questions($quiz, $addonpage, $categoryid, 1, $includesubcategories);
+    quiz_delete_previews($quiz);
+    quiz_update_sumgrades($quiz);
     redirect($returnurl);
 }