How to notifyPropertyChange eachComputedProperty when you Ember.defineProperty

I have a spot in my controller when I add a new computed. (as shown below). But later when I read all the computed properties it doesn't have this new property. How can I break the cache/or update the "eachComputedProperty" to reflect each new computed I add on the fly?

Ember.defineProperty(this, "foobar", Ember.computed(function() {}));

This is how I'm looping over each computed

var factory = this.get("constructor.ClassMixin.ownerConstructor");
factory.eachComputedProperty(function(key) {});