diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 873486d62cca..5a6c62580735 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -712,5 +712,7 @@ function drupal_maintenance_theme() {
   require_once './includes/common.inc';
   require_once './includes/unicode.inc';
   unicode_check();
+  drupal_add_css(drupal_get_path('module', 'system') .'/defaults.css', 'core');
+  drupal_add_css(drupal_get_path('module', 'system') .'/system.css', 'core');
   $theme = '';
 }