Ember-data transforms aren't applying with ember-cli

Project setup:

• Ember: 2.0.0
• Ember-data: 2.0.0
• Ember-cli: 1.13.8

I have created a transform:

import DS from 'ember-data';

export default DS.Transform.extend({

    deserialize: function(serialized) {
        serialized = window.moment(serialized).toDate();
        if(serialized.toString() === "Invalid Date"){serialized = null}
        return serialized;
    },

    serialize: function(deserialized) {
        deserialized = window.moment(deserialized).toISOString();
        return deserialized;
    }
});

and used it like so:

import Ember from 'ember';
import DS from 'ember-data';

export default DS.Model.extend({
    Forename: DS.attr('string'),
    Surname: DS.attr('string'),
    Gender: DS.attr('string'),
    DOB: DS.attr('isodate'),
});

But the transform is not being applied. Has something changed in ember 2.0 that hasn't been updated on the docs that would result in the above not working?