How do you get wrinkles out of a raincoat?

I never thought of ironing my raincoat. Everytime after used, I 'll hang it dry and then folded it back. It never come into my mind about ironing it. but is really a good question. I think about it very hard and search in the internet but couldn't find any solution provided. Maybe nobody ever think of it before. So you are the first one. But do you want to get rid the wrinkles because it is very hard to fold your raincoat nicely flat? Then maybe you can try rolling them up tightly after you have folded them flat. The next day when it rains, hopefully the raincoat will not that wrinkled (due to overlong stretch).Thanks