Borussia Dortmund have pushed through their option to sign Paco Alcacer from Barcelona on a permanent basis.
Striker Alcacer joined Dortmund on loan in August after failing to get the amount of minutes he wanted at Camp Nou.
"Dortmund was and is the correct decision for me," the Spain forward said.
Dortmund have paid 21 million euros to sign Alcacer, who has signed a deal with the German club until 2023.
"We've let Barcelona know that we will execute the option to buy. Paco has become an essential part of our team," sporting director Michael Zorc said.
Alcacer joined the Bundesliga side on loan in exchange for a two million feel, pushing the total cost so far to 23 million euros.
A series of add-ons could see the price eventually end up closer to 30 million euros.
The former Valencia man's had an excellent start to the season, scoring nine goals in eight games and earning his place back in Luis Enrique's Spain squad.