diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index d28316b..aebfa14 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -1572,6 +1572,7 @@ function _menu_tree_data(&$links, $parents, $depth) {
  * Implements template_preprocess_HOOK() for theme_menu_tree().
  */
 function template_preprocess_menu_tree(&$variables) {
+  $variables['#tree'] = $variables['tree'];
   $variables['tree'] = $variables['tree']['#children'];
 }