diff --git a/course/modlib.php b/course/modlib.php
index 8ece656e681..2e03ff615fd 100644
--- a/course/modlib.php
+++ b/course/modlib.php
@@ -179,6 +179,7 @@ function add_moduleinfo($moduleinfo, $course, $mform = null) {
  */
 function edit_module_post_actions($moduleinfo, $course) {
     global $CFG;
+    require_once($CFG->libdir.'/gradelib.php');
 
     $modcontext = context_module::instance($moduleinfo->coursemodule);
     $hasgrades = plugin_supports('mod', $moduleinfo->modulename, FEATURE_GRADE_HAS_GRADE, false);