Help with Constructor in IIFE?

I’m stuck on setting up Coffeerun, specifically on the Constructors section. For some reason, the constructor for the DataStore function refuses to work. Chrome Dev Tools gives this error:

error

Moving the code outside the IIFE works fine. Anyway, here’s my code. I’ve checked and rechecked it. I googled it. I’ve checked StackOverflow, but I can’t figure out the problem. As far as I can tell, it should work find. Ignore the Poop() constructor. That was for testing purposes and is unrelated.

Any help is appreciated…

(function (window) {
  'use strict';
  var App = window.App || {};

  function DataStore() {
    console.log('running the DataStore function');
    this.data = {};
  }

  App.Datastore = DataStore;
  window.App = App;
})(window);

function Poop () {
  console.log('here is your poop object');
  this.poopData = {};
}

Annnnnnnd Nevermind. What a difference case can make…