My friend wears a size 12 in mens shoes would this be dumb?

I am buying him a pair of heavy duty boots for christmas and was wondering if a size 13 would be dumb to buy since he wears 12...the store only sells fricken 13 and he realllly likes them but doesnt know i am buying them do u think theyll fit okay? should i do that? sorry kinda dumb Q but input would be nice