diff --git a/mod/quiz/locallib.php b/mod/quiz/locallib.php
index 75848947e2e..75fd3eb94e0 100644
--- a/mod/quiz/locallib.php
+++ b/mod/quiz/locallib.php
@@ -1935,7 +1935,7 @@ class qubaids_for_quiz extends qubaid_join {
         }
 
         if ($onlyfinished) {
-            $where .= ' AND state == :statefinished';
+            $where .= ' AND state = :statefinished';
             $params['statefinished'] = quiz_attempt::FINISHED;
         }