Sleep help

My 6 month old loves to sleep on his stomach. He’s able to roll on his stomach and then into his back no problem. The problem now is that he’s at the very early stages of wanting to crawl and loves to rock back and forth. It’s pretty fun for him! My problem is that when I lay him down for naps or for bedtime, he immediately flips over into his stomach. I know it’s okay to leave him on his stomach if he does it in the middle of the night but should I leave him if he rolls over within seconds of being placed on his back?