What to do to avoid a promotion?

I've been notified by 2 higher-ups on 2 different occasions, that I will probably get promoted soon, because there's an opening. But I don't want the additional responsibilities. I really like the place where I am at right now. I get along with everyone, I have good bonuses, not too much pressure on getting the work done, because I always come through. It's like the best middle ground to be in.
But this promotion implies managing everyone, recruiting, firing and probably a lot of staying after hours and sleepless nights.
However at the same time you can't just say "No, thanks", can you?