"No route matches" error in rspec, but route shows up in rake routes

Here is my route from routes.rb:

resources :books, :except => [:new, :edit] do

    post "pull" => "books#update", :data => { "pull" => true }

rake routes shows things as expected

pull_api_v1_book POST  /api/v1/books/:id/pull(.:format)  
    api/v1/books#update {:format=>:json, :data=>{"pull"=>true}}

Running a dev server, the route works as expected:

curl -X POST  http://localhost:3000/api/v1/books/3/pull?auth_token=1234567890

My spec in in books_controller_spec.rb:

post :pull, params: { :id => 12 }

But the output of the spec:

 Failure/Error: post :pull, params: { :id => 12 }

 ActionController::UrlGenerationError:
   No route matches {:action=>"pull", :controller=>"api/v1/books", :id=>12}

Why can't rspec find the route?