California has outlawed child marriage, joining 17 other US states where the taboo practice is also banned.

Under past state law, minors of any age could obtain a court order for marriage with the consent of their parents.

Assembly bill 1267, which governor Gavin Newsom signed on Wednesday, prohibits minors from being issued a marriage license or establishing a domestic partnership (an arrangement that provides spousal protections). The law has no exceptions.

“This is a long overdue measure to protect young Californians and minors. Today, California kids are safer than ever before,” Newsom said in a statement.

He was joined on Wednesday by activist Courtney Stodden, who was thrust into the public eye in 2011 when at 16 she married 51-year-old actor Doug Hutchison in Las Vegas, a union she has since reflected on with deep regret.

“Governor Newsom’s action today made clear to me and to survivors of child marriage everywhere that we should never have been expected to carry this burden,” Stodden said in a statement. “I’m deeply grateful to Unchained At Last and every survivor who fought to make this possible – California is a victory, but I’m not stopping here. I will keep fighting until children are protected from marriage in all 50 states.”

Unchained at Last, the advocacy group that pushed for the legislation, says 9,000 children are married in California every year.