`Ember.run.cancelTimers` is not a public API but is recommended here: https://ember-concurrency.com/docs/testing-debugging It's not even documented as a private API: https://api.emberjs.com/ember/release/modules/@ember%2Frunloop Nor is it documented as part of Backburner's API https://github.com/BackburnerJS/backburner.js/tree/master