Nevada’s attempt to prohibit “ghost guns” suffered a major setback following a state district court decision filed Friday.

The judge ruled in favor of the plaintiff, unfinished-gun-frame manufacturer Polymer80. He found two separate provisions of the state’s “ghost gun” ban were unconstitutionally vague and lacked objective enforcement standards.

“Nevadans would face the risk of discriminatory enforcement by police and prosecutors alike as they, in their sole discretion and without guidance, could label almost anything an ‘unfinished frame or receiver,’ if it in any way even resembles a firearm’s undefined frame or lower receiver,” Nevada state court judge John Schlegelmilch said in his ruling.

The court’s decision marks a reversal of fortunes for unfinished-firearms manufacturers and gun-rights activists alike. Earlier this July, a U.S. District Court judge partially dismissed a suit against the law filed by the Firearms Policy Coalition which sought to block it on Second Amendment grounds.

The ban established by AB 286, originally slated to go into effect Jan. 1, 2022, would prohibit a person from possessing, purchasing, transporting, or receiving any unfinished frame or receiver of a firearm, or assembling any firearm not imprinted with a serial number. Violations of the law would result in a criminal misdemeanor, while repeat offenses would be subject to felony charges.

Judge Schlelemilch in this case compared Nevada’s attempt to regulate “ghost guns” to those undertaken by the Biden administration. He criticized the state legislature’s failure to define the components they seek to outlaw.

“Unlike the federal regulatory process to determine whether a frame or lower receiver is considered a firearm under the Gun Control Act, Nevada has established no authority at all to determine when an ‘unfinished frame or receiver’ actually comes into existence,” he said.

He pointed out that during the trial, representatives of the state failed to define the terms set out in the law despite being asked by the court on several occasions.

“Tellingly, the Defendants could not in any manner explain their meaning(s),” Schlelemilch said. “As a result, this Court finds that the text of AB 286 does not provide fair notice of whatever it criminalizes.”

Representatives of Polymer80 praised the court’s ruling.

“This is a significant victory for Polymer80, Nevadans, and our customers nationwide,” Polymer80 CEO Loran Kelley said in a statement. “AB286 is vague and unlawful legislation that targets our company specifically for conducting a lawful business. We will continue to challenge lawless attempts to curtail our rights and the rights of our customers.”

Governor Steve Sisolak (D.), the defendant in the suit, did not respond to a request for comment.