Using match with namespace

I have namespace "admin" and controller "Accounts" with namespace "Admin". And Controller Accounts has method change_password. I want have route admin/accounts/change_password.

For this I try using member

namespace :admin do

resources :accounts do   member do     get :change_password   end end

end

But my method "change_password" does not have identificator(1) (admin/ accounts/1/change_password/).

What can I use for this?