Kerem Demirbay has signed a new four-year contract with Hoffenheim, the club have announced.
The 24-year-old, who joined from Hamburg two years ago, has agreed to a deal that will run until the end of the 2021-22 season.
Director of football Alexander Rosen told the Bundesliga side's official website that the extension was "a strong signal, both internally and externally, and underpins that we are resolutely pursuing our ambitious and successful path from recent years".
"Something special has emerged here and I'm convinced a lot more is possible," said the midfielder, who has two caps for Germany.
"The past few weeks especially has confirmed this to me again. In my time injured, I've experienced this incredible support again, which has been given to me since my transfer to Hoffenheim."
Nagelsmann's side sit seventh in the table.