diff --git a/cookbook/security/api_key_authentication.rst b/cookbook/security/api_key_authentication.rst
index da7de4f8502..18027be259f 100644
--- a/cookbook/security/api_key_authentication.rst
+++ b/cookbook/security/api_key_authentication.rst
@@ -16,8 +16,14 @@ passed as a query string parameter or via an HTTP header.
 The API Key Authenticator
 -------------------------
 
+.. versionadded:: 2.8
+    The ``SimplePreAuthenticatorInterface`` interface was moved to the
+    ``Symfony\Component\Security\Http\Authentication`` namespace in Symfony
+    2.8. Prior to 2.8, it was located in the
+    ``Symfony\Component\Security\Core\Authentication`` namespace.
+
 Authenticating a user based on the Request information should be done via a
-pre-authentication mechanism. The :class:`Symfony\\Component\\Security\\Core\\Authentication\\SimplePreAuthenticatorInterface`
+pre-authentication mechanism. The :class:`Symfony\\Component\\Security\\Http\\Authentication\\SimplePreAuthenticatorInterface`
 allows you to implement such a scheme really easily.
 
 Your exact situation may differ, but in this example, a token is read
@@ -27,13 +33,13 @@ value and then a User object is created::
     // src/AppBundle/Security/ApiKeyAuthenticator.php
     namespace AppBundle\Security;
 
-    use Symfony\Component\Security\Core\Authentication\SimplePreAuthenticatorInterface;
+    use Symfony\Component\HttpFoundation\Request;
+    use Symfony\Component\Security\Core\Authentication\Token\PreAuthenticatedToken;
     use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
     use Symfony\Component\Security\Core\Exception\AuthenticationException;
-    use Symfony\Component\Security\Core\Authentication\Token\PreAuthenticatedToken;
-    use Symfony\Component\HttpFoundation\Request;
-    use Symfony\Component\Security\Core\User\UserProviderInterface;
     use Symfony\Component\Security\Core\Exception\BadCredentialsException;
+    use Symfony\Component\Security\Core\User\UserProviderInterface;
+    use Symfony\Component\Security\Http\Authentication\SimplePreAuthenticatorInterface;
 
     class ApiKeyAuthenticator implements SimplePreAuthenticatorInterface
     {
@@ -273,9 +279,9 @@ you can use to create an error ``Response``.
     // src/AppBundle/Security/ApiKeyAuthenticator.php
     namespace AppBundle\Security;
 
-    use Symfony\Component\Security\Core\Authentication\SimplePreAuthenticatorInterface;
     use Symfony\Component\Security\Core\Exception\AuthenticationException;
     use Symfony\Component\Security\Http\Authentication\AuthenticationFailureHandlerInterface;
+    use Symfony\Component\Security\Http\Authentication\SimplePreAuthenticatorInterface;
     use Symfony\Component\HttpFoundation\Response;
     use Symfony\Component\HttpFoundation\Request;
 
@@ -506,8 +512,8 @@ for security reasons. To take advantage of the session, update ``ApiKeyAuthentic
 to see if the stored token has a valid User object that can be used::
 
     // src/AppBundle/Security/ApiKeyAuthenticator.php
-    // ...
 
+    // ...
     class ApiKeyAuthenticator implements SimplePreAuthenticatorInterface
     {
         // ...
diff --git a/cookbook/security/custom_password_authenticator.rst b/cookbook/security/custom_password_authenticator.rst
index c71995b7402..ca1f02775a2 100644
--- a/cookbook/security/custom_password_authenticator.rst
+++ b/cookbook/security/custom_password_authenticator.rst
@@ -21,8 +21,14 @@ The Password Authenticator
 .. versionadded:: 2.6
     The ``UserPasswordEncoderInterface`` interface was introduced in Symfony 2.6.
 
+.. versionadded:: 2.8
+    The ``SimpleFormAuthenticatorInterface`` interface was moved to the
+    ``Symfony\Component\Security\Http\Authentication`` namespace in Symfony
+    2.8. Prior to 2.8, it was located in the
+    ``Symfony\Component\Security\Core\Authentication`` namespace.
+
 First, create a new class that implements
-:class:`Symfony\\Component\\Security\\Core\\Authentication\\SimpleFormAuthenticatorInterface`.
+:class:`Symfony\\Component\\Security\\Http\\Authentication\\SimpleFormAuthenticatorInterface`.
 Eventually, this will allow you to create custom logic for authenticating
 the user::
 
@@ -30,13 +36,13 @@ the user::
     namespace Acme\HelloBundle\Security;
 
     use Symfony\Component\HttpFoundation\Request;
-    use Symfony\Component\Security\Core\Authentication\SimpleFormAuthenticatorInterface;
     use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
     use Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken;
     use Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface;
     use Symfony\Component\Security\Core\Exception\AuthenticationException;
     use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
     use Symfony\Component\Security\Core\User\UserProviderInterface;
+    use Symfony\Component\Security\Http\Authentication\SimpleFormAuthenticatorInterface;
 
     class TimeAuthenticator implements SimpleFormAuthenticatorInterface
     {