As if the Patriots’ signing of Antonio Brown didn’t seem sneaky enough, there’s another wrinkle to his contract.

The team added an option year onto Brown’s one-year contract which would pay Brown $20 million guaranteed for the 2020 NFL season if the Patriots exercise the option, according to ESPN, which said the option was added for “cap proration purposes.”

After the Raiders cut Brown on Saturday, the Patriots pounced and gave Brown a one-year deal worth up to $15 million, including a $9 million signing bonus.

Brown received a $1 million fully guaranteed base salary for this season, has $500k in game-day roster bonuses and three $1.5 million incentives, according to NFL Network: one for reaching 105 catches, another for reaching 1,298 yards receiving and another for 16 touchdowns. He’d have to reach those marks in 15 games.

But after losing roughly $30 million in guaranteed money once the Raiders fined him for conduct detrimental to the team, Brown could end up with $35 million over the next two seasons if the Patriots want to bring him back.

The Patriots tried to trade for Brown in March before the Steelers dealt the 31-year-old to the Raiders.