diff --git a/mysql/backup.pl b/mysql/backup.pl
index ab9c5fadf..2ecae607e 100755
--- a/mysql/backup.pl
+++ b/mysql/backup.pl
@@ -98,7 +98,7 @@ foreach $db (@dbs) {
 				"root",
 				$config{'backup_single_'.$sf},
 				$config{'backup_quick_'.$sf},
-				0,
+				undef,
 				$config{'backup_parameters_'.$sf}
 			       );
 	if ($err) {