diff --git a/phpgwapi/inc/class.preferences.inc.php b/phpgwapi/inc/class.preferences.inc.php
index f973d6a092..6ea86bbf47 100644
--- a/phpgwapi/inc/class.preferences.inc.php
+++ b/phpgwapi/inc/class.preferences.inc.php
@@ -132,7 +132,7 @@
 		*/
 		function add($app_name,$var,$value = '')
 		{
-			if (! $value)
+			if ($value == '')
 			{
 				global $$var;
 				$value = $$var;