diff --git a/phpgwapi/inc/class.egw_db.inc.php b/phpgwapi/inc/class.egw_db.inc.php
index 043e125d01..f2d462a60b 100644
--- a/phpgwapi/inc/class.egw_db.inc.php
+++ b/phpgwapi/inc/class.egw_db.inc.php
@@ -1674,7 +1674,7 @@ class egw_db
 	 */
 	function expression($table_def,$args)
 	{
-		if (!is_array($table_def)) $table_def = $this->get_table_definitions('',$table_def);
+		if (!is_array($table_def)) $table_def = $this->get_table_definitions(true,$table_def);
 		$sql = '';
 		$ignore_next = 0;
 		foreach(func_get_args() as $n => $arg)