An autographed collectible sold in California will need to come with a certificate that verifies it's not a forgery under legislation signed by Gov. Jerry Brown.
Brown signed the bill Friday to crack down on selling items with fake celebrity signatures.
The proposal won the support of actor Mark Hamill earlier this year.
Best known for his portrayal of Luke Skywalker in "Star Wars" films, Hamill often uses his Twitter account to sort out whether something has his genuine signature on it or has been forged.
AB 1570, by Assemblywoman Ling-Ling Chang (R-Diamond Bar), expands consumer protections that currently are limited to fake signatures on sports memorabilia.
The new law will take effect in January.
“In a way, it seems futile to try and counter what is clearly a very lucrative market,” Hamill told The Times earlier this year. “But we can’t let them get away with it.”