diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index 3065b722..1e61e0bb 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -3590,14 +3590,6 @@ class SFTP extends SSH2
         if (!$this->precheck()) {
             return false;
         }
-        $testA = $this->version >= 5;
-        $testB = isset($this->extensions['posix-rename@openssh.com']) && $this->extensions['posix-rename@openssh.com'] === '1';
-        if (!$testA && !$testB) {
-            throw new \RuntimeException(
-                "Extension 'posix-rename@openssh.com' is not supported by the server. " .
-                "Call getSupportedVersions() to see a list of supported extension"
-            );
-        }
 
         $oldname = $this->realpath($oldname);
         $newname = $this->realpath($newname);
@@ -3608,9 +3600,14 @@ class SFTP extends SSH2
         if ($this->version >= 5) {
             $packet = Strings::packSSH2('ssN', $oldname, $newname, 2); // 2 = SSH_FXP_RENAME_ATOMIC
             $this->send_sftp_packet(NET_SFTP_RENAME, $packet);
-        } else {
+        } elseif (isset($this->extensions['posix-rename@openssh.com']) && $this->extensions['posix-rename@openssh.com'] === '1') {
             $packet = Strings::packSSH2('sss', 'posix-rename@openssh.com', $oldname, $newname);
             $this->send_sftp_packet(NET_SFTP_EXTENDED, $packet);
+        } else {
+            throw new \RuntimeException(
+                "Extension 'posix-rename@openssh.com' is not supported by the server. " .
+                "Call getSupportedVersions() to see a list of supported extension"
+            );
         }
 
         $response = $this->get_sftp_packet();