AC/DC co-founder Malcolm Young has retired from the band. The Australian hard rock group announced the release of their new album as they confirmed Young’s exit.

In April, the group confirmed that the 61-year-old guitarist has been suffering from an undisclosed illness, but denied that they would all be retiring as a band.

As drummer Phil Rudd insisted at that time, the band will live on forever.

“We were never going to retire. It’ll never happen. Angus [Young, guitarist] will never retire and as long as Angus never retires, I won’t f------ retire either,” he told AAP.

And as he swore, the band is still up and about and is set to release its new album “Rock or Bust” in December. Unfortunately, though, Young will not be joining the group anymore.

“’Rock or Bust’ is the first AC/DC album in the band’s 41 year history without founding member Malcolm Young on the recordings,” the group wrote on its official Web site.

“Earlier this year, AC/DC released a statement explaining that due to illness, Malcolm would be taking a break from the band. Unfortunately, due to the nature of Malcolm’s condition, he will not be returning to the band. AC/DC will undertake a world tour in support of ‘Rock or Bust’ in 2015. Stevie Young, nephew of founding members Angus and Malcolm Young, plays rhythm guitar on ‘Rock or Bust’ and will accompany the band on tour.”

The band refuses to divulge the nature of Young’s illness.

Apart from Angus, Stevie and Rudd, the band is also joined by current members Cliff Williams and Brian Johnson.

AC/DC was formed by the Young brothers in 1973. The new studio album “Rock or Bust” will be released on December 2.

Read: AC/DC to Rock Forever Despite Malcolm Young’s Illness, Drummer Phil Rudd Says