diff --git a/src/wp-admin/includes/class-ftp.php b/src/wp-admin/includes/class-ftp.php
index f068f157bd..bee9fa1f36 100644
--- a/src/wp-admin/includes/class-ftp.php
+++ b/src/wp-admin/includes/class-ftp.php
@@ -504,7 +504,7 @@ class ftp_base {
 		return $this->_list(($arg?" ".$arg:"").($pathname?" ".$pathname:""), "LIST", "rawlist");
 	}
 
-	function nlist($pathname="") {
+	function nlist($pathname="", $arg="") {
 		return $this->_list(($arg?" ".$arg:"").($pathname?" ".$pathname:""), "NLST", "nlist");
 	}