config.expire_auth_token_on_timeout not working in devise 3.2.4 with rails 3.2.13

Using devise 3.2.4 with rails 3.2.13.

I am trying to expire auth token on session timeout therefore in my devise.rb file , I have made following changes :-

config.timeout_in = 1.minutes config.expire_auth_token_on_timeout = true

The timeout works perfectly, user is logged out after 1 minute of inactivity period but the auth token is not expiring on timeout.

Here is the user model:-

  devise :database_authenticatable, :async , :registerable, :confirmable,
     :recoverable, :rememberable, :trackable, :validatable, :omniauthable, :timeoutable  

Any idea what I am missing ?