Chris Cornell and Tom Morello perform together for the "15 Now" Benefit Show at El Corazn on Sept. 26, 2014 in Seattle.

Chris Cornell would've turned 55 years old on Saturday (July 20). Tom Morello celebrated the occasion by sharing a heartfelt message dedicated to his late Audioslave bandmate on social media.

The Rage Against the Machine guitarist began the brief note by explaining how his kids have recently discovered Audioslave's music. They particularly like the supergroup's 2002 song "Cochise."

"While rocking out hard to Cochise my oldest stopped and said, 'Dad, it’s really sad that Chris Cornell is dead.' I replied, 'That is very true, but let’s keep rocking out.' And we did. Happy Birthday, Chris," Morello captioned a photo of Cornell on Twitter and Instagram.

Morello and Cornell spent many successful years together in Audioslave, releasing three studio albums from 2002 through 2006. The band also consisted of bassist Tim Commerford and drummer Brad Wilk.

The legendary Soundgarden frontman died by suicide in May 2017. Prior to his death, Soundgarden had been working on the follow-up album to the band's 2012's reunion album, King Animal.

See Morello's birthday tribute to Cornell below.