diff --git a/system/Controller.php b/system/Controller.php
index 45fe0e499565..c040e1d20a4f 100644
--- a/system/Controller.php
+++ b/system/Controller.php
@@ -65,7 +65,7 @@ class Controller
     /**
      * Once validation has been run, will hold the Validation instance.
      *
-     * @var ValidationInterface
+     * @var ValidationInterface|null
      */
     protected $validator;