diff --git a/password_strength.module b/password_strength.module
index f192543..0c9bf9e 100644
--- a/password_strength.module
+++ b/password_strength.module
@@ -15,7 +15,7 @@ define('PASSWORD_STRENGTH_SCORE_VERYSTRONG', 4);
  * Implements hook_xautoload().
  */
 function password_strength_xautoload($api) {
-  $api->namespaceRoot('ZxcvbnPhp', 'lib/zxcvbn-php/src');
+  $api->addPsr4('ZxcvbnPhp', 'lib/zxcvbn-php/src');
 }
 
 /**