Can I stop the mouse from interacting with masked image?

Alright, is there some way to keep a clip with masked content from reacting to the mouse? I’ve got a button clip with a masked image inside (so the image that goes beyond the button’s bounds can’t be seen), but, when the mouse rolls over the masked-off image area, the button still reacts. I’ve been looking for a few days now, and I can absolutely not figure out what to do! Thanks for whatever help can be given.