Mark Hamill Is Helping Star Wars Fans Beat Shady Memorabilia Dealers

Mark Hamill is helping Star Wars superfans verify his autograph on memorabilia in order to “beat the dealers.”

The actor has been responding to fans on Twitter asking the star to confirm his signature before they purchase posters and other items allegedly signed by the star.

Hamill, who debuted as Luke Skywalker in the franchise’s original installment back in 1977, first broke the bad news to one user that his handwriting is often faked.

“I’m so sorry there’s so many fans spending their hard-earned money for fraudulent signatures,” the actor, 64, wrote.

He encouraged fans to “look at the signatures I verified to learn to spot the forgeries for yourself. #BeatTheDealers.”

“Memorize this REAL signature and you can start spotting the phonies yourself! #BeatTheDealers,” Hamill added.

When one follower asked Hamill if he was “getting tired” of confirming signatures on the social media website, he praised his fan base and explained that he wanted to prevent people from being swindled.

“I owe it to all true fans to protect them from being victimized by dishonest dealers,” he wrote.

Hamill returned to the film series in box office giant Star Wars: The Force Awakens, but the extent of his role has been largely shrouded in mystery as it is a major plot point of the movie. (We, of course, won’t spoil the film for fans here!)

This article originally appeared on People.com.