The She Looks So Perfect hitmakers are currently working on the follow-up to their 2014 self-titled debut album and are preparing to sit down with Sixx to come up with new material.
The bassist shared the news with fans on Twitter.com on Sunday (29Mar15) after congratulating the boys on their Best Fan Army win at the iHeartRadio Music Awards, where bandmember Michael Clifford was photographed wearing a Motley Crue T-shirt.
Sixx wrote, "Congrats @5sos on your award Nice Crüe shirt too. See yah next week for some lyric writing."
The boys later reposted the message on their official Twitter account.
5 Seconds of Summer are also reuniting with longtime collaborators Joel and Benji Madden, from Good Charlotte, and producer John Feldman for their sophomore project.
Frontman Luke Hemmings recently said of the Madden twins, "They've had a big role in the album this time, even more so than the last album. It's been really fun. We really look up to them, their whole movement as a band. It's amazing they're on board with us. They're great dudes."