Roma have completed the permanent signing of Antonio Rudiger from Stuttgart after exercising their option to buy the Germany international.
Rudiger joined Roma on a one-year loan deal ahead of the 2015-16 campaign for an initial fee of EUR4million and the Serie A side have now paid an additional EUR9m to land the defender on a permanent deal.
"Roma have exercised their option to buy Antonio Rudiger and have thus signed the 23-year-old on a permanent basis," a statement on the Stuttgart website reads.
"The agreement between both sides contains a set transfer fee, a number of variables plus a sell-on fee for VfB.
"VfB wish Antonio Rudiger all the best for the future, in particular for the upcoming European Championship in France."
Rudiger was a key figure for Roma in 2015-16, scoring twice in 30 Serie A appearances to help the Stadio Olimpico side to third place in the table behind champions Juventus and runners-up Napoli.
Stuttgart, meanwhile, dropped to the 2.Bundesliga without Rudiger as they finished 17th.