If there’s one thing you could never accuse Radiohead of being it’s nostalgic. The group is not wont to rest on its laurels or hang around in one place for very long, but eagle-eyed fans have noticed some (literal) signs that Thom Yorke and the gang might be preparing to go back to the future and celebrate one of their musical mountaintops.

Posters spotted by fans in cities including London, New York, Los Angeles, Amsterdam and Berlin seem to reference lyrics from the song “Fitter Happier” from Radiohead’s landmark third album, 1997’s OK Computer. The posters seem to have different messages on them, but each end with the years 1997-2017. OK Computer, which signaled a push into more the more electronic, experimental mode the band has maintained ever since, was released on May 21, 1997 and has since become one of the group’s most revered works. The posters have spawned lots of speculation on Reddit.

The band has not announced any anniversary events (and a spokesperson could not be reached for comment at press time), but check out the posters and see for yourself:

No! #fear #poster #billboard #friedrichshain #plakat #berlin #morefear #pasteup

A post shared by Tim Schnetgoeke (@timschnetgoeke) on Apr 23, 2017 at 12:35pm PDT

#Shoreditch. Pretty peak Shoreditch, in fact. Tunnels. Graffiti. Arches. A very deep and meaningful message about today's society. What more could you want? . . . #graffiti #arhes #tunnel #lights #lightandshade #morefear #shoreditchhighstreet #shoreditchlondon #shoreditchhighstreetstation #society #socialcommentary #hipster #streetart

A post shared by Alina Polianskaya (@ally_poli) on Apr 25, 2017 at 2:57am PDT

More Fear. #morefear #charingcrossroad #posterart #graffiti #centrallondon

A post shared by Patrick Baker 🔶🔷🔶 🍀🇮🇪✊🏻 (@kerrybhoy65) on Apr 22, 2017 at 9:09am PDT

This story originally appeared on Billboard.