diff --git a/classes/observer.php b/classes/observer.php
index ddb7a41..17ece7f 100644
--- a/classes/observer.php
+++ b/classes/observer.php
@@ -6,7 +6,7 @@ defined('MOODLE_INTERNAL') || die();
 
 class observer
 {
-    public static function check_course_completion(\core\event\course_module_completion_updated $event)
+    public static function check_course_completion(\mod_quiz\event\attempt_submitted $event)
     {
         global $DB;