Ember CP Validations validate uniqueness of two fields

I have a field that I want to check if it's unique in my store. There are tons of tutorial on how to do this, but for my particular uniqueness it depends on the value of another value in the form. I need to check if the combined value is unique. Anyone have an idea on how to do this? The only solution I can think of is using a computed property (two fields combined), and having a validator on that. That seems kind of messy though.