Sunderland have signed France defender Nordi Mukiele from Paris St-Germain in a deal worth £12m, taking their summer spending to around £141.5m.
The 27-year-old's arrival on a four-year contract comes a day after they beat West Ham 3-0 on their return to the top flight.
Mukiele, who spent last season on loan at Bundesliga side Bayer Leverkusen, is the 12th player to sign for the Black Cats this summer.
He will cost an initial 11m euros (£9.5), with a further 3m euros (£2.5m) in add-ons.
"It's a new challenge and I'm happy to be here," said Mukiele.