Sead Kolasinac has agreed to join Bundesliga side Schalke on loan for the rest of the season, Arsenal announced on Thursday.
The Bosnia defender, 27, will head back to the club where he joined the youth set-up and went on to become a first-team regular before moving to the Premier League in June 2017.
Kolasinac's loan move is set to begin on January 4. The full-back has made 113 appearances for Arsenal.
Arsenal technical director Edu told the club website: "Sead needs to be playing regularly, so we have decided together that a move back to Germany with Schalke will benefit him at this moment.
"We will be keeping in close contact with Sead, and wish him huge success for the remainder of the season with Schalke."
Schalke are currently bottom of the Bundesliga with just four points and without a win all season.