diff --git a/question/editlib.php b/question/editlib.php
index 965b0a19c19..e968f68d916 100644
--- a/question/editlib.php
+++ b/question/editlib.php
@@ -608,7 +608,7 @@ abstract class question_bank_action_column_base extends question_bank_column_bas
 
     public function get_required_fields() {
         // createdby is required for permission checks.
-        return array('q.id, q.createdby');
+        return array('q.id', 'q.createdby');
     }
 }