Nabil Bentaleb will become a Schalke player on a permanent basis at the end of his season-long loan from Tottenham.
The 22-year-old Algerian midfielder was allowed to move to the Bundesliga last August after dropping out of Mauricio Pochettino's plans at White Hart Lane.
He has performed strongly in Germany, adding a goalscoring element to his game that was absent at Tottenham by netting four times already.
Schalke stated the deal would run until 2021. The fee involved is undisclosed.