diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index f2872efb..baa03a10 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -1909,6 +1909,9 @@ class SFTP extends SSH2
             if ($local_start >= 0) {
                 fseek($fp, $local_start);
                 $size -= $local_start;
+            } elseif ($mode & self::RESUME) {
+                fseek($fp, $offset);
+                $size -= $offset;
             }
         } elseif ($dataCallback) {
             $size = 0;