Baby rolling to his stomach in his sleep. Help!

I'm sure this has been asked a million and one times, but I'm sleep deprived and not searching just the right wording to find helpful posts. My perfect sleeper 7 month old recently learned how to roll to his stomach in his sleep. That's cool, except he HATES being on his stomach, doesn't seem to realize he put himself there, and something about the middle of the night makes him forget he can roll to his back independently. This has turned him into a terrible sleeper. Last night he woke up at 11:45, 3, 3:30, 3:45... you get the point. I'm exhausted. He's exhausted. The pets are considering revolt. Please send any words of wisdom. Should I leave him to figure it out on his own? Put him back on his back and pray he stays that way for at least an hour? Is this just one of those things he'll get used to with time?