[H] TvT Proxy Maur Aggression

So in TvT I occasionally like to open with proxy rax Marauder with concussive early aggression. If I keep them busy, I can expand behind it etc. But the snap back if they scout it is MASSIVE, and they just a-click into my pretty empty base while I'm marauding around in their base. What do you guys do to defend your own base while you do this (besides the wall off ofc.) Don't want to base trade every game.

Thanks, yes? =D