In announcing that he was coming out of retirement in March, Floyd Mayweather said that all UFC champion Conor McGregor had to do was “sign the paperwork” for their boxing match to become reality.

Conor McGregor has signed the paperwork.

“It is an honour to sign this record breaking deal alongside my partners Zuffa LLC, The Ultimate Fighting Championship and Paradigm Sports Management,” the UFC lightweight champion told on Thursday in a statement. “The first, and most important part of this historic contract has now officially been signed off on. Congratulations to all parties involved. We now await Al Haymon and his boxer’s signature in the coming days.”

Now it’s up to Mayweather, who hasn’t set foot in the ring since September 2015. According to TheMacLife, MMA President Dana White said last weekend that he wanted to secure McGregor’s signature before working out a deal with Mayweather. Last month, White said he anticipated that Mayweather would earn $100 million from the bout — he has previously said that he wouldn’t come out of retirement for anything less — and McGregor $75 million, though the boxer could very well want more.

The proposed boxing match between Mayweather, a champion in four weight classes over his career, and McGregor has been the talk of the fight game for nearly two years now even though McGregor never has trained strictly as a boxer. But the possibility of seeing the most prominent boxer in recent history going up against MMA’s biggest draw has been an enticing prospect, simply for the novelty of it.

John Kavanagh, McGregor’s coach, said last month that McGregor has been focusing solely on traditional boxing in his training at the expense of wrestling, jiu jitsu and Thai boxing, fighting styles he employs in his MMA bouts. McGregor’s girlfriend gave birth to their son earlier this month, however, and the UFC champion has said he wouldn’t begin training in earnest for the Mayweather fight until after he became a father.

McGregor acknowledged both the prospective bout and his newborn son in a tweet Thursday morning.