Ake vows to improve further after becoming Cherries' record signing
Bournemouth have signed Chelsea defender Nathan Ake for a club record fee of £20m.
The 22-year-old Holland international, who spent the first half of last season on loan with the Cherries, has put pen to paper on a long-term deal at the Vitality Stadium.
He joins former Sunderland striker Jermain Defoe, who completed a move to Bournemouth on Thursday.
Ake scored three goals in 12 appearances for Bournemouth last season before being recalled in January by Chelsea, where he featured sporadically as Antonio Conte's side won the Premier League title.
Ake said: "I had a great time here last season so I'm happy to be back. It's an exciting challenge. Chelsea is a great club and I learned so much but this is a new step and the right place for me to develop even more.
"The fans haven't seen the best of me yet. I always set the bar high so I know there is a lot of things I still have to work on.
"I know I can keep improving and become a better player."