Unswaddle?

Today when Mason was fussing his way into a nap he rolled over onto his tummy. He has been getting close to rolling over for a while now but it is really easy for him when he is unswaddled. He also woke himself up early out of another nap by rolling over again. This freaked me out! I did not like going in there to see he was face down...(I know that he can and will turn his head but I still did not like it!).
I was at a loss for what to do - do I completely unswaddle him to keep him from rolling, do I half way unswaddle. So I decided to experiment. For bedtime I tried swaddling only his lower half - he HATED it! Was super upset and did not want to get to sleep. So I reswaddled him completely and he we right to sleep. I rolled a few blankets and wedged them under his hips so he cannot roll over. I guess he is just going to have to sleep this way for a while because he does not want to be unswaddled yet!