diff --git a/phpgwapi/inc/class.categories.inc.php b/phpgwapi/inc/class.categories.inc.php
index 0ef6597e46..26a514c4eb 100644
--- a/phpgwapi/inc/class.categories.inc.php
+++ b/phpgwapi/inc/class.categories.inc.php
@@ -811,7 +811,7 @@ class categories
 		// check if we are already updated to global owner == 0, if not do it now
 		if (!$GLOBALS['egw']->db->select(self::TABLE,'COUNT(*)','cat_owner=0',__LINE__,__FILE__)->fetchColumn())
 		{
-			$GLOBALS['egw']->db->update(self::TABLE,'cat_owner=0','cat_owner=-1',__LINE__,__FILE__);
+			$GLOBALS['egw']->db->update(self::TABLE,'cat_owner=0',"(cat_owner=-1 OR cat_appname='phpgw')",__LINE__,__FILE__);
 			$GLOBALS['egw']->db->insert(self::TABLE,array(
 				'cat_main'    => 0,
 				'cat_parent'  => 0,