diff --git a/mod/scorm/locallib.php b/mod/scorm/locallib.php
index 7e6cea5a770..45715d4300e 100644
--- a/mod/scorm/locallib.php
+++ b/mod/scorm/locallib.php
@@ -1569,6 +1569,7 @@ function scorm_format_toc_for_treeview($user, $scorm, $scoes, $usertracks, $cmid
     $result = new stdClass();
     $result->prerequisites = true;
     $result->incomplete = true;
+    $result->toc = '';
 
     if (!$children) {
         $attemptsmade = scorm_get_attempt_count($user->id, $scorm);