diff --git a/doku.php b/doku.php
index 54b1d00e9b23791318d39fb41633bd7dced1cd9a..52e8e6b8e9597db80a96ad2a6fa37389b2867089 100644
--- a/doku.php
+++ b/doku.php
@@ -12,7 +12,7 @@ if(!defined('DOKU_INC')) define('DOKU_INC',dirname(__FILE__).'/');
 
 if (isset($_SERVER['HTTP_X_DOKUWIKI_DO'])){
     $ACT = trim(strtolower($_SERVER['HTTP_X_DOKUWIKI_DO']));
-} elseif (!empty($IDX)) {
+} elseif (!empty($_REQUEST['idx'])) {
     $ACT = 'index';
 } elseif (isset($_REQUEST['do'])) {
     $ACT = $_REQUEST['do'];