How to teach puppy to go down my stairs?

My puppy is nearly 6 months now but he is terrified to go down the stairs inside my apartment. The weird thing is he will go up the stairs with absolutely no problem at all. If I try to get him to come back down he is very scared and refuses to go down. Its very bothersome because if I’m in my living room and he takes a notion to go up the stairs I have to bring him back down because he is unable to come back down. Any advice on how to teach him to go down the steps?