diff --git a/setup.php b/setup.php
index 8916d168..2b99c19d 100644
--- a/setup.php
+++ b/setup.php
@@ -23,6 +23,8 @@
  * Form POST \ GET Variables: -none-
  */
 
+define('POSTFIXADMIN', 1); # checked in included files
+
 require_once("languages/en.lang");
 require_once("functions.inc.php");