How to configure FOSUserBundle to be the authentication provider for my FOSOAuthServerBundle enabled server

I am trying to set up FOSUserBundle to be the authentication provider for my FOSOAuthServerBundle enabled server. The FOSOAuthServerBundle has been working correctly prior to me trying to implement FOSUserBundle and I have also had FOSUserBundle working without FOSOAuthServerBundle, but I just can't get them working together.

My question is what should be specified for the authentication provider in the oauth_authorize: firewall in the security.yml below?

# app/config/security.yml
security:
    providers:
    fos_userbundle:
        id: fos_user.user_provider.username

    encoders:
        FOS\UserBundle\Model\UserInterface: sha512

    firewalls:
        oauth_token:
            pattern:    ^/oauth/v2/token
            security:   false

        oauth_authorize:
            pattern:    ^/oauth/v2/auth

            # WHAT GOES HERE?

        api:
            pattern:    ^/api
            fos_oauth:  true
            stateless:  true

    access_control:
        - { path: ^/api, roles: [ IS_AUTHENTICATED_FULLY ] }

I am trying to authenticate the users and not the client.

Many thanks.