diff --git a/include/functions.inc.php b/include/functions.inc.php
index 39b618d81..10d6c8f2d 100644
--- a/include/functions.inc.php
+++ b/include/functions.inc.php
@@ -1559,7 +1559,7 @@ function load_language($filename, $dirname = '', $options = array())
   }
   $dirname .= 'language/';
 
-  $default_language = defined('PHPWG_INSTALLED') and !defined('UPGRADES_PATH') ?
+  $default_language = (defined('PHPWG_INSTALLED') and !defined('UPGRADES_PATH')) ?
       get_default_language() : PHPWG_DEFAULT_LANGUAGE;
 
   // construct list of potential languages