Defender Trai Hume has signed a new four-year contract with Sunderland, to run to the summer of 2027.
The 21-year-old Northern Ireland international scored two goals in 34 games for the Black Cats last season, including the play-off semi-finals.
Hume, who previously played for Linfield and Ballymena, established himself as a first-team regular under boss Tony Mowbray last season.
"I'm still young and I'm certainly looking to play games," Hume said.
"Hopefully we can have another good season but there is lots of work over the summer."
Sporting director Kristjaan Speakman added: "Trai was very patient in his first twelve months and worked tirelessly to refine his game.