How do I test for a 204 response in RSpec in Rails?

I am testing the delete action of my resource controller as follows:

describe ResourceController do
  context "DELETE destroy" do
    before :each do
      delete :destroy, id: @resource.id
    end
    it { should respond_with(:no_content) }
  end
end

I expect a 204/no-content response. However, this test is failing as the response returned by the server is a 406. The response is a 204 when I hit the controller directly from my Rest test client.