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.
Bentaleb leaves Tottenham after 66 appearances and one goal.
Tottenham said in a statement: "We have reached agreement with FC Schalke 04 for the permanent transfer of Nabil Bentaleb this summer.