Saving parameters with dat.gui.min.js

Throws error in console: Uncaught TypeError: Cannot read property 'forEach' of undefined (dat.gui.min.js:3)

HTML

<script src="http://dat-gui.googlecode.com/git/build/dat.gui.min.js"></script>

JavaScript

var obj = { x: 5 };
var gui = new dat.GUI();
gui.add(obj, 'x');
gui.remember(obj);