diff --git a/plugins/OStatus/classes/HubSub.php b/plugins/OStatus/classes/HubSub.php
index 3120a70f9f..c420b3eef8 100644
--- a/plugins/OStatus/classes/HubSub.php
+++ b/plugins/OStatus/classes/HubSub.php
@@ -192,7 +192,7 @@ class HubSub extends Memcached_DataObject
 
         // Any existing query string parameters must be preserved
         $url = $this->callback;
-        if (strpos('?', $url) !== false) {
+        if (strpos($url, '?') !== false) {
             $url .= '&';
         } else {
             $url .= '?';