diff --git a/src/Symfony/Component/Security/Core/Authorization/Voter/Voter.php b/src/Symfony/Component/Security/Core/Authorization/Voter/Voter.php
index 8d36fd8f8c..2396b1e678 100644
--- a/src/Symfony/Component/Security/Core/Authorization/Voter/Voter.php
+++ b/src/Symfony/Component/Security/Core/Authorization/Voter/Voter.php
@@ -74,6 +74,7 @@ abstract class Voter implements VoterInterface
 
     /**
      * Perform a single access check operation on a given attribute, subject and token.
+     * It is safe to assume that $attribute and $subject already passed the "supports()" method check.
      *
      * @param string         $attribute
      * @param mixed          $subject