diff --git a/mod/quiz/report/grading/report.php b/mod/quiz/report/grading/report.php
index 3f88c059ade..fd19f3b4977 100644
--- a/mod/quiz/report/grading/report.php
+++ b/mod/quiz/report/grading/report.php
@@ -68,7 +68,7 @@ class quiz_report extends quiz_default_report {
         echo '<div id="overDiv" style="position:absolute; visibility:hidden; z-index:1000;"></div>'; // for overlib
 
         if ($data = data_submitted()) {  // post data submitted, process it
-            confirm_sesskey();
+            require_sesskey();
 
             // now go through all of the responses and save them.
             foreach($data->manualgrades as $uniqueid => $response) {