Jack White dropped in on Pearl Jam's headlining set at Portugal's NOS Alive festival last night, joining the band on guitar for a cover of the Neil Young classic "Rockin' in the Free World."

Frontman Eddie Vedder welcomed White to the stage for the final song. You can watch fan-shot video of their "Rockin' in the Free World" performance below. Pearl Jam has previously performed "Rockin' in the Free World" with Young himself, and the song has been a longtime Pearl Jam set list staple.

Two songs earlier in the encore set, the band first teased an appearance by White (who had just finished his own set at the festival) by playing the riff from the White Stripes' 2003 hit "Seven Nation Army" during their jam on the Ten track, "Porch." Accounts vary as to whether White joined in on that as well; according to JamBase, he was merely seen watching from the wings at the time.

White last joined forces with Pearl Jam in 2016, when he joined them for a performance of their then-unreleased "Of the Earth" at a small, secret Third Man Nashville show prior to Bonnaroo. White later released the recording in one of his Third Man Vault packages.

Like Pearl Jam, White began touring this year after a two-year hiatus. Pearl Jam finishes their European tour on July 17 in London, before returning to the U.S. for a tour of baseball stadiums that kicks off on Aug. 8 at Safeco Field in their hometown of Seattle. White, too, is wrapping up a European tour, playing in Finland tonight, before resuming his tour in the U.S. with a Lollapalooza set on Aug. 5.