diff --git a/question/engine/questionusage.php b/question/engine/questionusage.php
index c09083e2a9b..9fa6e0ce0b2 100644
--- a/question/engine/questionusage.php
+++ b/question/engine/questionusage.php
@@ -646,6 +646,7 @@ class question_usage_by_activity {
      * @param string $comment the comment being added to the question attempt.
      * @param number $mark the mark that is being assigned. Can be null to just
      * add a comment.
+     * @param int $commentformat one of the FORMAT_... constants. The format of $comment.
      */
     public function manual_grade($slot, $comment, $mark, $commentformat = null) {
         $qa = $this->get_question_attempt($slot);
diff --git a/question/engine/tests/unitofwork_test.php b/question/engine/tests/unitofwork_test.php
index f83de5ca6e4..027bf3f73d0 100644
--- a/question/engine/tests/unitofwork_test.php
+++ b/question/engine/tests/unitofwork_test.php
@@ -174,7 +174,7 @@ class question_engine_unit_of_work_test extends data_loading_method_test_base {
 
     public function test_process_action() {
 
-        $this->quba->manual_grade($this->slot, 'Acutally, that is not quite right', 0.5, FORMAT_HTML);
+        $this->quba->manual_grade($this->slot, 'Actually, that is not quite right', 0.5, FORMAT_HTML);
 
         // Here, however, were we are adding a step to an existing qa, we do need to track that.
         $this->assertEquals(0, count($this->observer->get_attempts_added()));