Symfony-2.5 - Can't use access_control in security.yml for ROLE_ADMIN

Question

here is my security.yml file

security:
    access_denied_url: home
    encoders:
        Coupon\MainBundle\Entity\User:
            algorithm: sha512
            iterations: 1
            encode_as_base64: true

    role_hierarchy:
        ROLE_ADMIN:       [ROLE_USER]
        ROLE_SUPER_ADMIN: [ROLE_ADMIN]

    providers:
        main:
            entity: { class: CouponMainBundle:User }

    firewalls:
        secured_area:
            pattern:    ^/
            form_login:
                check_path: _auth_check
                always_use_default_target_path: true
                default_target_path: /dut
                login_path: /
            logout:
                path:   action_logout
                target: action_login
            anonymous: ~

    access_control:
        - { path: ^/admin.*, role: ROLE_ADMIN }

but when try to go to /admin with user who has ROLE_ADMIN (var_dump for getRoles returns array(2) { [0]=> string(10) "ROLE_ADMIN" [1]=> string(9) "ROLE_USER" }), it redirects me to home page, can you help me ? where is my fault ?