diff --git a/deployment.rst b/deployment.rst
index 9023d5e28a3..7f64175376f 100644
--- a/deployment.rst
+++ b/deployment.rst
@@ -231,7 +231,7 @@ kernel and return your project's root directory::
 
         public function getProjectDir()
         {
-            return __DIR__.'/..';
+            return dirname(__DIR__);
         }
     }