SEATTLE (AP) — A federal appeals court panel has unanimously rejected a challenge to Washington's law requiring background checks for gun transfers.

Washington voters approved Initiative 594 in 2014. It requires people transferring a firearm to go through a federally licensed firearms dealer to conduct a background check on the buyer, even for private sales or sales at gun shows.

The initiative brought a lawsuit from gun rights advocates who claimed it would infringe on their Second Amendment rights, and the Legislature made some fixes, for example by making it clear that people don't need to run background checks before sharing guns while hunting.

That satisfied some of the groups that brought the lawsuit, but others, including Bellevue gun rights advocate Alan Gottlieb, said the law still infringed on their rights. Among other things, they argued that it bars couples that live together from transferring guns to each other if they're not married.

The 9th U.S. Circuit Court of Appeals panel said the remaining plaintiffs did not have standing to challenge the law because they had not shown a credible threat that they might be prosecuted.