diff --git a/conf/z-push.conf.php b/conf/z-push.conf.php
index 1c4c02f..1b3e642 100644
--- a/conf/z-push.conf.php
+++ b/conf/z-push.conf.php
@@ -54,7 +54,7 @@
      *   false - use the username only.
      *   true  - string the mobile sends as username, e.g. full email address (default).
      */
-    define('USE_FULLEMAIL_FOR_LOGIN', true);
+    define('USE_FULLEMAIL_FOR_LOGIN', false);
 
 /**********************************************************************************
  * StateMachine setting