Bundesliga champions Bayer Leverkusen have signed French teenager Jeanuel Belocian from Ligue 1 side Rennes until 2029, the German club announced on Friday.
Sky Germany reported the centre-back arrived for a fee of 15 million euros ($16.2 million).
Calling the defender "a great talent", Leverkusen sporting director Simon Rolfes said the 19-year-old "has the potential to become an important player for Bayer Leverkusen".
Belocian said joining Leverkusen was "incredible", calling this season's breakthrough title run under Xabi Alonso "fantastic".
Leverkusen won the Bundesliga title for the first time last season and claimed the domestic double by beating Kaiserslautern 1-0 in the German Cup final.
The club's only defeat of the season came in the Europa League final against Serie A club Atalanta in late May.