Biting me!

My son will be 1 on November 14th. He eats solids, but still nurses every 4 hours. I love it. He loves it. I don't plan on stopping until he wants to stop. He currently has 5 teeth. They haven't been an issue nursing (occasionally it felt a like they would unintentionally scrape my nipple) until a few days ago. He keeps biting my nipple! Hard af! I say ow! ( out of instinct) then tell him no biting. And he laughs at me and does it again and I put my boob away. Anyone have any suggestions as to how to get him to stop this? I do not want to stop nursing or start bottle feeding.