California Gov. Jerry Brown has vetoed a controversial bill that would have allowed children in the state to legally have more than two parents.
Brown, who supports gay marriage, said he was concerned that passing the legislation would lead to a slippery slope.
"I am troubled by the fact that some family law specialists believe the bill's ambiguities may have unintended consequences," Brown said in a statement Sunday.
"I am returning Senate Bill 1476 without my signature," he continued. "I would like to take more time to consider all of the implications of this change."
Traditional marriage supporters opposed the law because it redefined two-parent families and could have helped same-sex couples involved in custody battles.
Sponsors of the bill said they "fully expect a bill of this type to return" and will continue to work to get the legislation passed.
The legislation came about after the California Court of Appeals ruled that judges can never find that a child has more than two parents, regardless of the situation.