diff --git a/src/Symfony/Component/Validator/Validator.php b/src/Symfony/Component/Validator/Validator.php
index 8221d60266..202e1e2f10 100644
--- a/src/Symfony/Component/Validator/Validator.php
+++ b/src/Symfony/Component/Validator/Validator.php
@@ -52,7 +52,7 @@ class Validator implements ValidatorInterface
         MetadataFactoryInterface $metadataFactory,
         ConstraintValidatorFactoryInterface $validatorFactory,
         TranslatorInterface $translator,
-        $translationDomain = null,
+        $translationDomain = 'validators',
         array $objectInitializers = array()
     )
     {