diff --git a/core/modules/toolbar/toolbar.module b/core/modules/toolbar/toolbar.module
index e1d55f3..0e5e26a 100644
--- a/core/modules/toolbar/toolbar.module
+++ b/core/modules/toolbar/toolbar.module
@@ -443,7 +443,7 @@ function toolbar_toolbar() {
   // add that JSONP script. We add it as an external script, because it's a
   // Drupal path, not a file available via a stream wrapper.
   // @see toolbar_subtrees_jsonp()
-  $menu['toolbar_administration']['#attached']['js'][url('toolbar/subtrees/' . _toolbar_get_subtree_hash())] = array('type' => 'external');
+  $menu['toolbar_administration']['#attached']['js'][url('toolbar/subtrees/' . _toolbar_get_subtree_hash())] = array('type' => 'external', 'attributes' => array('defer' => TRUE));
 
   // The administration element has a link that is themed to correspond to
   // a toolbar tray. The tray contains the full administrative menu of the site.