Define product types allowed in wish list

Hi Everyone,

I feel like this must be here, I simply can't find where to set it. Can someone point me in the correct direction?

I have a series of products, but I also have products that are membership items. I don't want someone to be able to add the membership item to their wish list, simply because there is no real point.

Is there an easy way to define which product types are eligible for adding to a wish list.

Thanks so much.