If you don’t want The Last Jedi spoiled for you, then you probably will want to stay away from the Star Wars comic books. Mark Hamill took to Twitter to warn fans — perhaps jokingly, perhaps not — that a 1977 comic book will spoil the upcoming installment of the franchise.

“I’m begging you! For your own good-DO NOT READ this spoiler-laden comic book before Friday December 15th 2017 You’ll thank me later,” Hamill tweeted.

Obviously, Hamill did not let out any plot details of the aforementioned comic — which shares the same name of Episode VIII.  From his sense of urgency, it seems that it contains major plot points for The Last Jedi — or maybe it’s just a lighthearted joke that people are taking too seriously. But if the tweet is true, some diehard fans who have read this comic book may already know what to expect in the forthcoming movie directed by Rian Johnson.

The Star Wars cinematic universe has been subject to a lot of speed bumps as of late. Phil Lord and Chris Miller exited the Han Solo stand alone and were replaced by Ron Howard. Recently, Colin Trevorrow was relieved of his directing duties of Episode IX and was replaced by J.J. Abrams. Even so, the latest Stars Wars films, Rogue One and The Force Awakens have taken extreme measures to keep major plot points under lock and key.