SEATTLE, Wash. (AP) — A Western Washington US District Court judge has affirmed a set of firearms regulations approved by Washington voters in 2018, ruling against a legal challenge raised by gun-right advocates.

I-1639 raised the legal purchase age of a semiautomatic rifle to 21 and established enhanced background checks for their purchase, passing with nearly 60% support.

The Seattle Times reports the judge cited federal law that bans sales of handguns to people under 21 and age restrictions that have been imposed since the 1800’s under state laws.

The Bellevue-based Second Amendment Foundation says the group plans to appeal.