diff --git a/phpseclib/Net/SFTP/Stream.php b/phpseclib/Net/SFTP/Stream.php
index 89a0e59b2..ccbc09ac0 100644
--- a/phpseclib/Net/SFTP/Stream.php
+++ b/phpseclib/Net/SFTP/Stream.php
@@ -447,7 +447,9 @@ private function _stream_metadata($path, $option, $var)
         //     and https://github.com/php/php-src/blob/master/main/php_streams.h#L592
         switch ($option) {
             case 1: // PHP_STREAM_META_TOUCH
-                return $this->sftp->touch($path, $var[0], $var[1]);
+                $time = isset($var[0]) ? $var[0] : null;
+                $atime = isset($var[1]) ? $var[1] : null;
+                return $this->sftp->touch($path, $time, $atime);
             case 2: // PHP_STREAM_OWNER_NAME
             case 3: // PHP_STREAM_GROUP_NAME
                 return false;