How do I import a Transform object from Ember Data for extending

I would like to extend Ember Data's date model field (http://ift.tt/2vvnIrW). How do I import this object into a transforms/ file in my project? I have tried the following:

import DateTransform from 'ember-data/transforms/date';

export default DateTransform.extend({
    [deserialize and serialize overridden methods here]
});

This does not work, and does not provide any sort of error in console. I feel like I simply have something wrong with the file path in the import statement, but I cannot figure out what it is.