The 22-year-old put pen to paper on a new deal earlier this year but the Blaugrana have rewarded the winger again in a bid to increase his buy-out clause, which now stands at €25 million.
He told Barcelona's official website: "I’m very happy to have renewed. It’s a dream to be able to stay for so many more years at this club.
“I hope things remain as good as they are and that I can get to play. I’ll be taking all the chances the boss gives me and trying to do my best for the club.”
Tello is a Barca academy product , and he have made 29 games with them.
