Name Error: uninitialized constant

I'm running the tests after editing the controller, and Jason's first test passed, but both of mine are failing. I've already triple checked all the code and I believe it's identical. I can't seem to find where my mistake is.

This is the error I'm getting: Failures:

1) Viewing todo items displays the title of the todo list Failure/Error: click_link "List Items" NameError: uninitialized constant TodoItemsController::Todolist # ./app/controllers/todo_items_controller.rb:3:in index' # ./spec/features/todo_items/index_spec.rb:9:inblock (3 levels) in <top (required)>' # ./spec/features/todo_items/index_spec.rb:8:in `block (2 levels) in <top (required)>'

2) Viewing todo items displays no items when a todo list is empty Failure/Error: click_link "List Items" NameError: uninitialized constant TodoItemsController::Todolist # ./app/controllers/todo_items_controller.rb:3:in index' # ./spec/features/todo_items/index_spec.rb:9:inblock (3 levels) in <top (required)>' # ./spec/features/todo_items/index_spec.rb:8:in `block (2 levels) in <top (required)>'

My todo_items_controller.rb looks like this:

class TodoItemsController < ApplicationController
  def index
    @todo_list = Todolist.find(params[:todo_list_id])
  end
end

My todo_items index.html.erb:

<h1><%= @todo_list.title %></h1>
<p>Find me in app/views/todo_items/index.html.erb</p>

And my index_spec.rb:

require 'spec_helper'

describe "Viewing todo items" do
    let!(:todo_list) {TodoList.create(title: "Grocery list", description: "Groceries")}

    before do
        visit "/todo_lists"
        within "#todo_list_#{todo_list.id}" do
            click_link "List Items"
        end
    end


    it "displays the title of the todo list" do
        within("h1") do
            expect(page).to have_content(todo_list.title)
        end
    end 

    it "displays no items when a todo list is empty" do
        expect(page.all("ul.todo_items li").size).to eq(0)
    end
end

Please help!