Mixin both instance and class methods in Ruby

I have a Ruby class into which I want to include both class and instance methods. Following the pattern described in "Ruby Pattern: Extend through Include", I'm currently using the following:

class SomeObject

  include SomeObject::Ability

  def self.some_builder_method(params)
    # use some_class_method ...
  end

end

module SomeObject::Ability

  module ClassMethods

    def some_class_method(param)
      # ...
    end

  end

  def self.included(klass)
    klass.extend(ClassMethods)
  end

  def some_instance_method
    # ...
  end

end

I'd rather not make two separate modules, one being included and the other being extended, because all the methods in my module logically fit together. On the other hand, this pattern requires me to:

1. Define an additional ClassMethods module.
2. Write a boilerplate self.included method for every module.

Is this the most idiomatic way to approach this?