The Brazil international signed a five-year deal in 2021 with the clause added in to make it more straightforward to tie him down for longer, and it is understood the English Premier League club have now exercised that option.
Alisson missed Tuesday's Champions League defeat to Galatasaray in Istanbul due to a minor problem sustained in training but head coach Arne Slot is hopeful the 33-year-old will be fit enough to return for Sunday's Premier League visit of Tottenham.
Slot has urged his players to "get the maximum" out of the remainder of their season but admitted he does not know what that will be.
A 1-0 defeat against Galatasaray leaves his side with work to do for next week's home Champions League last-16 second leg while they remain behind their rivals in the race for a top-five spot in the Premier League.
An FA Cup quarter-final trip to Manchester City next month will also provide a serious challenge to their other hope of winning silverware this season.
"What I want is that every single player gets the maximum out of every single training session and games we are playing from now until the end of the season," Slot said ahead of the visit of a hopelessly out of form Tottenham.
"That is the aim for me and that should be the aim for the players because that's the only way to get the maximum out of what is there, what is in it for us.
"What that's exactly going to be, that's not always so easy to say in advance because sometimes you need a little bit of luck."