diff --git a/template.php b/template.php
index e41b72e27cd9bba3892d5b2a54ba0dd9b5af2c87..110635d5dd4c96eade9e1c5478445de25f6d7a0f 100644
--- a/template.php
+++ b/template.php
@@ -24,7 +24,7 @@ if (theme_get_setting('zen_rebuild_registry') && !defined('MAINTENANCE_MODE')) {
  * Implements HOOK_theme().
  */
 function zen_theme(&$existing, $type, $theme, $path) {
-  include_once './' . drupal_get_path('theme', 'zen') . '/zen-internals/template.theme-registry.inc';
+  include_once DRUPAL_ROOT . '/' . drupal_get_path('theme', 'zen') . '/zen-internals/template.theme-registry.inc';
   return _zen_theme($existing, $type, $theme, $path);
 }