He KNOWS it is your accomplishment even if you phrase otherwise.
You know best how to ask but I would definitely say something. It never hurts to ask in private why he does this to you since he has done it before.....maybe there is something that needs to be cleared up about what he is doing.
Without communicating anything it will only continue to happen & he may think it doesm't matter to you. Who knows if there is a motive behind it or not unless there is communication.....otherwise it is speculation & assumptions. At least if you hear his rational you can better determine if your speculation is correct.