diff --git a/quiz.pages.inc b/quiz.pages.inc
index 20c393f..aeba876 100644
--- a/quiz.pages.inc
+++ b/quiz.pages.inc
@@ -222,10 +222,12 @@ function quiz_update_total_score_fast($rid, $quiz_vid) {
 		->addField('qnp', 'max_score');
 	$res2 = $subq2->execute()->fetchField();
 
-	db_update('quiz_node_results')
-		->expression('score', 'ROUND(100*(:res1/:res2))', array(':res1' => $res1, ':res2' => $res2))
-		->condition('result_id', $rid)
-		->execute();
+  ($res2==0) ? $rounded=100 : $rounded=round($res1/$res2);
+
+  db_update('quiz_node_results')
+    ->expression('score', ':round', array(':round' => $rounded))
+    ->condition('result_id', $rid)
+    ->execute();
 }
 
 /**