diff --git a/question/engine/questionusage.php b/question/engine/questionusage.php
index b4a1a29527e..c5ee03daa49 100644
--- a/question/engine/questionusage.php
+++ b/question/engine/questionusage.php
@@ -310,10 +310,8 @@ class question_usage_by_activity {
     }
 
     /**
-     * Get the current mark awarded for the attempt at a question.
-     * @param int $slot the number used to identify this question within this usage.
-     * @return number|null The current mark for this question, or null if one has
-     * not been assigned yet.
+     * Get the total mark for all questions in this usage.
+     * @return number The sum of marks of all the question_attempts in this usage.
      */
     public function get_total_mark() {
         $mark = 0;