diff --git a/airtime_mvc/application/common/HTTPHelper.php b/airtime_mvc/application/common/HTTPHelper.php
index 5f06a3f9d..80e6fd16e 100644
--- a/airtime_mvc/application/common/HTTPHelper.php
+++ b/airtime_mvc/application/common/HTTPHelper.php
@@ -37,7 +37,7 @@ class Application_Common_HTTPHelper
         if ($baseDir[0] != "/") {
             $baseDir = "/" . $baseDir;
         }
-        if ($baseDir[strlen($baseDir)-1] != "/") {
+        if (substr($baseDir, -1) != "/") {
             $baseDir = $baseDir . "/";
         }