diff --git a/extlib/OAuth.php b/extlib/OAuth.php
index fd48535545..648627b576 100644
--- a/extlib/OAuth.php
+++ b/extlib/OAuth.php
@@ -327,7 +327,7 @@ class OAuthRequest {/*{{{*/
   public function get_normalized_http_url() {/*{{{*/
     $parts = parse_url($this->http_url);
 
-    $port = @$parts['port'];
+    $port = isset($parts['port']) ? $parts['port'] : null;
     $scheme = $parts['scheme'];
     $host = $parts['host'];
     $path = @$parts['path'];