installing an Ember helper through add on then using it in a component breaks the tests

I'm installing the 'ember-moment' helper and then I'm using it in components. As soon as I do that, those components' tests break saying pretty much nothing:

not ok 120 PhantomJS 1.9 - StatusCardComponent: it renders
---
    actual: >
        null
    message: >
        Died on test #2     at http://localhost:7357/assets/test-support.js:2779
            at test (http://localhost:7357/assets/test-support.js:1796)
            at http://localhost:7357/assets/client.js:11190
            at http://localhost:7357/assets/vendor.js:150
            at tryFinally (http://localhost:7357/assets/vendor.js:30)
            at http://localhost:7357/assets/vendor.js:156
            at http://localhost:7357/assets/test-loader.js:29
            at http://localhost:7357/assets/test-loader.js:21
            at http://localhost:7357/assets/test-loader.js:40
            at http://localhost:7357/assets/test-support.js:5545: Assertion Failed: A helper named 'moment' could not be found
    Log: >
...

I tried a bunch of ways of adding this helper to the test as a dependency, but nothing worked and I can't find any information about it. Help is much appreciated.