How to stop AI from using my ship designs?

I actually really enjoy that they use them. It's amazing from a galaxy-scale roleplay perspective - with every game it fleshes out the characters more and more, since I try to develop the civs' identities through ship shapes and names as I play them. It also helps to increase the difficulty a bit, "teaching" them to use better loadouts. But just in case, if I wanted a clean slate, is there a way to make them use only their stardock-designed default ships?