diff --git a/mod/quiz/db/services.php b/mod/quiz/db/services.php
index 12591be16b5..bdd52c7d90e 100644
--- a/mod/quiz/db/services.php
+++ b/mod/quiz/db/services.php
@@ -61,6 +61,7 @@ $functions = array(
         'methodname'    => 'get_user_best_grade',
         'description'   => 'Get the best current grade for the given user on a quiz.',
         'type'          => 'read',
-        'capabilities'  => 'mod/quiz:view'
+        'capabilities'  => 'mod/quiz:view',
+        'services'      => array(MOODLE_OFFICIAL_MOBILE_SERVICE)
     ),
 );