diff --git a/src/Symfony/Component/Security/Core/User/EquatableInterface.php b/src/Symfony/Component/Security/Core/User/EquatableInterface.php
index e67ebfaadf..e2bde9e066 100644
--- a/src/Symfony/Component/Security/Core/User/EquatableInterface.php
+++ b/src/Symfony/Component/Security/Core/User/EquatableInterface.php
@@ -26,6 +26,9 @@ interface EquatableInterface
      * However, you do not need to compare every attribute, but only those that
      * are relevant for assessing whether re-authentication is required.
      *
+     * Also implementation should consider that $user instance may implement
+     * the extended user interface `AdvancedUserInterface`.
+     *
      * @param UserInterface $user
      *
      * @return Boolean