Timothy Fosu-Mensah has signed a new contract at Manchester United that will keep him at the club until June 2020.
The 18-year-old defender, whose previous terms had been due to expire at the end of the season, has signed a deal that has an option for a further year.
"I am delighted to have signed a new contract here at Manchester United," Fosu-Mensah told the club's official website.
"I have enjoyed every minute since I joined this great club and I want to continue the progress that I feel I have made so far.
"I am learning every day from the manager and the coaching staff. I appreciate the trust that the club has in me and I want to repay that with my performances on the pitch."
Fosu-Mensah, who joined United in 2014, was handed his first-team debut by Louis van Gaal against Arsenal last season, coming off the bench in a 3-2 win in February.
He has since made 11 further appearances for the senior team, though only two of those have come since the appointment of Van Gaal's successor Jose Mourinho, who expects the Dutchman to be involved more later in the season.
"Tim is young player with great potential. I am pleased that he has signed a new contract and I am delighted at the progress he has made so far," Mourinho said.
"It is clear to see that he is learning every day in training and there will be plenty of opportunities for him as the season continues."
