diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index 4b670280705..9f9d71b1696 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -5493,6 +5493,7 @@ class assign {
 
         $adminconfig = $this->get_admin_config();
         $gradebookplugin = $adminconfig->feedback_plugin_for_gradebook;
+        $gradebookplugin = str_replace('assignfeedback_', '', $gradebookplugin);
         $grades = $DB->get_records('assign_grades', array('assignment'=>$this->get_instance()->id));
 
         $plugin = $this->get_feedback_plugin_by_type($gradebookplugin);