Chelsea have announced that they have completed the signing of Hakim Ziyech from Ajax.
They agreed a deal with the Dutch club on 13 Feburary and have now finalised personal terms with the winger.
He will join Chelsea at the end of the 2019/20 season on a five-year contract.
"I am delighted and proud to have signed for such a huge club as Chelsea," Ziyech told the club's official website.
"I am looking forward to next season and hope we can achieve great things together."
Ziyech is a 26-year-old winger who can also play as a No 10.
This season he has produced eight goals and 21 assists in 32 matches across all competitions.
That tally includes an assist against Chelsea in a 4-4 draw in the UEFA Champions League group stage in November.
In 2018/19 he was named in the UEFA Champions League squad of the season after helping Ajax to the semi-finals.
Ziyech has been capped 32 times for Morocco, scoring 14 goals.