diff --git a/book/security.rst b/book/security.rst
index 1495c64084e..2be790c63f2 100644
--- a/book/security.rst
+++ b/book/security.rst
@@ -785,7 +785,7 @@ Take the following ``access_control`` entries as an example:
             # ...
             access_control:
                 - { path: ^/admin, roles: ROLE_USER_IP, ip: 127.0.0.1 }
-                - { path: ^/admin, roles: ROLE_USER_HOST, host: symfony.com }
+                - { path: ^/admin, roles: ROLE_USER_HOST, host: symfony\.com$ }
                 - { path: ^/admin, roles: ROLE_USER_METHOD, methods: [POST, PUT] }
                 - { path: ^/admin, roles: ROLE_USER }
 
@@ -793,7 +793,7 @@ Take the following ``access_control`` entries as an example:
 
             <access-control>
                 <rule path="^/admin" role="ROLE_USER_IP" ip="127.0.0.1" />
-                <rule path="^/admin" role="ROLE_USER_HOST" host="symfony.com" />
+                <rule path="^/admin" role="ROLE_USER_HOST" host="symfony\.com$" />
                 <rule path="^/admin" role="ROLE_USER_METHOD" method="POST, PUT" />
                 <rule path="^/admin" role="ROLE_USER" />
             </access-control>
@@ -809,7 +809,7 @@ Take the following ``access_control`` entries as an example:
                 array(
                     'path' => '^/admin',
                     'role' => 'ROLE_USER_HOST',
-                    'host' => 'symfony.com',
+                    'host' => 'symfony\.com$',
                 ),
                 array(
                     'path' => '^/admin',