ActionController::Base.helpers proxy fails for helper_method-helpers

In controller:

  class ApplicationController < ActionController::Base
  
    helper_method :quack!

    protected

      def quack!
        "Quack, quack!"
      end

  end

In view:

  = quack!  # => "Quack, quack!"
  = ActionController::Base.helpers.quack!  # => undefined method `quack!' for #<ActionView::Base:0x1058925c8>

Weird. I would like to state that I think this should work - I actually really needs to access helpers from outside of ActionView template in a few cases. I'm not sure why it's not working, because it seems like it was supposed to work according to the source:

http://github.com/rails/rails/blob/2-3-stable/actionpack/lib/action...