Who doesn't love a little anarchy? Over the weekend, fans at Download Festival in the U.K. were treated to a special collaboration as Nikki Sixx walked out onstage to join Megadeth for a rousing cover of the Sex Pistols classic, "Anarchy in the U.K."

Both Megadeth and Sixx have history with the song as each has covered it in the past, with Sixx's take coming during his time with Motley Crue. The song appeared on the Motley Crue collection, Decade of Decadence back in 1991. As for Megadeth, fans can trace the band's history with the song all the way back to the 1988 album So Far, So Good ... So What! album.

The guys appear to be having fun with it and the audience seems appreciative as Sixx trades licks with David Ellefson and Kiko Loureiro before making his way to the microphone and joining Dave Mustaine on vocals. As the song ends, Sixx embraces or shakes hands with all the band members, while Mustaine can be seen applauding the performance along with the crowd after Sixx exited the stage. Watch it all play out in the fan-shot video above.

Megadeth will remain in Europe through mid-July, then will take a small breather before heading to South America for shows in late July and August. See all of their dates here. Sixx: A.M., meanwhile, have a healthy schedule ahead of them too. Check out all of the band's tour dates here.

See Megadeth's Dystopia Among Our Best Metal Albums of 2016 (So Far)

Dave Mustaine Plays Wikipedia Fact or Fiction, Part 1