diff --git a/src/Symfony/Component/Validator/Constraints/Unique.php b/src/Symfony/Component/Validator/Constraints/Unique.php
index 391c4eaa13..743ec02e91 100644
--- a/src/Symfony/Component/Validator/Constraints/Unique.php
+++ b/src/Symfony/Component/Validator/Constraints/Unique.php
@@ -27,5 +27,5 @@ class Unique extends Constraint
         self::IS_NOT_UNIQUE => 'IS_NOT_UNIQUE',
     ];
 
-    public $message = 'This collection should contain only unique elements';
+    public $message = 'This collection should contain only unique elements.';
 }