Ian Maatsen has completed his loan move to Borussia Dortmund after signing a new Chelsea contract.
The Blues have awarded the academy graduate winger a two-year extension, taking his deal up to the summer of 2026.
A release clause is fitted into the renewal as Chelsea look to ramp up Maatsen's value with his upcoming stint in Germany.
"Borussia Dortmund made a lot of effort to sign me," Maatsen said. "I've been following BVB and their fans for a long time and even went to the Champions League match in Manchester in the autumn of 2022 to see the team live on the pitch.
"I'm very happy that the loan has now worked out. I promise that I'll give my all to help the team be successful and am really looking forward to the Yellow Wall."
Welcome to Dortmund, Ian! 👋 pic.twitter.com/rBZQUOLosz
— Borussia Dortmund (@BlackYellow) January 12, 2024
Initially kept on at the club over the summer once a £31.5million move to Burnley failed to come off, he has only made a single Premier League start.
Dortmund have agreed to pay the 21-year-old's full salary during his stay, for the rest of the season.
Maatsen arrives in North Rhine-Westphalia to bolster Borussia's underwhelming campaign, with Edin Terzic's side fifth in the Bundesliga and winless in six games.
Jadon Sancho is also set to sign for the club in a loan reunion following his nightmare spell at Manchester United.