Emre Can will join Borussia Dortmund permanently from Juventus in July on a deal that runs until 2024, the Bundesliga club has announced.
The 26-year-old Germany international initially moved to Dortmund in January on a loan deal that runs until the end of this campaign.
He scored on his first Bundesliga appearance in a 4-3 loss to Bayer Leverkusen and started last week's 4-0 thrashing of Eintracht Frankfurt.
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As part of the loan deal, Dortmund was obliged to buy Can for €25million if "sport results" were achieved, but the club has acted swiftly to reach an agreement just 18 days after the initial move.
"Bundesliga club Borussia Dortmund have reached an agreement with Italian record champions Juventus over the permanent transfer of Germany international Emre Can," read a statement on Dortmund's website.
"The 26-year-old's loan deal ends in June. As of 1 July, a valid contract between Borussia Dortmund and Can will enter into force and run until 30 June 2024."