Mark Hamill is determined to #BeatTheDealers. The Star Wars: The Force Awakens star hates that so many Star Wars fans have been duped with fake autographs on Star Wars memorabilia they’ve paid good money to procure.

Ask Mark Hamill before shelling out for #StarWars memorabilia! #BeatTheDealers #fansrule https://t.co/R5WLd2lwjE pic.twitter.com/8qzCEgShux

— Zap2it (@Zap2it) December 28, 2015

According to The Hollywood Reporter, Hamill is working with fans via Twitter to determine whether signatures on their merchandise are truly his or simply fakes.

It was Sunday night when Mark Hamill first checked out countless photos of merchandise bearing what they assumed was his signature. He was on Twitter doing so earlier on Monday as well.

Because I owe it to all true fans to protect them from being victimized by dishonest dealers! #FightFraud #FansRule https://t.co/aXk6zBMCAs

— Mark Hamill (@HamillHimself) December 28, 2015

So sorry to tell you it's not just a FAKE, but a horrible FAKE at that! #BeatTheDealers #FansRule https://t.co/ygBaPtr4b6

— Mark Hamill (@HamillHimself) December 28, 2015

Close call, but pretty sure it's FAKE. Misspelled name a good indicator of a fake (& I'm not that good an artist) https://t.co/kpKfP3ZPkq

— Mark Hamill (@HamillHimself) December 28, 2015

This is REAL Rob- Use this example to weed out the phonies. #FightFraud #BeatTheDealers #FansRule https://t.co/Zfx2oI8lc6

— Mark Hamill (@HamillHimself) December 28, 2015

Mark Hamill reprises his role as Luke Skywalker in Star Wars: The Force Awakens, which topped all prior Christmas box office premieres.

How Mark Hamill is helping #StarWars fans beat shady memorabilia dealers https://t.co/3Js9fhLXO1 pic.twitter.com/exZJ5Z0yVU

— People magazine (@people) December 28, 2015

Do you own any Star Wars merchandise with what you assume is Mark Hamill’s autograph? Check out his Twitter page for clear examples of both fakes and originals.