Andy Nicholson, bassist for British rock band The Arctic Monkeys, has permanently quit the band after dropping out of their North American tour last month.

“We are sad to tell everyone that Andy is no longer with the band,” said a statement from the band’s three other members on their web site. “We have been mates with Andy for a long time and have been through some amazing things together that no one can take away. We all wish Andy the very best.”

Nicholson blamed “fatigue following an intensive period of touring” for his initial departure in May.

The band said that his replacement for their upcoming summer shows will be Nick O’Malley, who filled in on bass during the recent tour of North America.