Lady Gaga and Michael Polansky, who have been secretly engaged for months, are hashing out a prenup before their upcoming wedding, In Touch has learned.

Gaga, 38, “is worth $900 million, so of course there needs to be a prenup in place,” says a source. “And Michael understands that. He’s not resisting it.”

Michael himself is extremely wealthy — the 46-year-old is executive director of the Parker Foundation and estimated to be worth $600 million!

“So there are a lot of assets on both sides, and a prenup will just make everything clear. It hasn’t created any tension between them — it’s actually made everything easier. They can’t wait to get married.”