The U.S. Supreme Court unanimously ruled on Tuesday that a man’s challenge to his former placement on the “No Fly List” can move forward, finding that the government failed to show his lawsuit is moot.

Yonas Fikre, a U.S. citizen who previously resided in Sudan, claimed his placement on the list was unlawful and sued the FBI.

The government later removed him from the list and signaled that it was unlikely he would be readmitted. It was then contended that Fikre’s lawsuit was moot as a result and should be tossed.

The government warned that not declaring lawsuits like Fikre’s moot at the onset could require the government to disclose classified information. The Supreme Court rejected that assertion, enabling Fikre’s case to move ahead.

As The Hill noted, Justice Neil Gorsuch stated in the court’s opinion, “Necessarily, our judgment is a provisional one.”

“Just because the government has not yet demonstrated that Mr. Fikre’s case is moot does not mean it will never be able to do so,” the conservative justice continued. “This case comes to us in a preliminary posture, framed only by uncontested factual allegations and a terse declaration. As the case unfolds, the complaint’s allegations will be tested rather than taken as true, and different facts may emerge that may call for a different conclusion.”

According to Fikre, he left his home in East Africa in late 2009 to pursue expanding an electronics company in Sudan. According to court documents, the FBI questioned Fikre while he was in Sudan and informed him that he was on the No Fly List and that if he turned informant, he might have his status removed.

Fikre reportedly declined and fled to the United Arab Emirates, where he says the secret police there kidnapped and tortured him for months at the FBI’s request. Fikre claims that he relocated to Sweden, filed his lawsuit, and requested asylum after departing the United Arab Emirates.

Sweden reportedly used a private jet to transport Fikre back to Portland, Oregon, after denying him asylum.

According to court documents, the government informed Fikre in 2016 that his lawsuit was moot and that he had been removed from the No Fly List. The 9th U.S. Circuit Court of Appeals overturned the district court’s decision, prompting the government to file an appeal with the Supreme Court.

Typically, the government withholds the complete rationale behind listing individuals, and the Justice Department voiced apprehensions that permitting cases like Fikre’s to proceed would unnecessarily compel the government to divulge its occasionally classified justifications.

“A case does not automatically become moot when a defendant suspends its challenged conduct and then carries on litigating for some specified period,” Gorsuch pushed back. “Nor can a defendant’s speculation about a plaintiff’s actions make up for a lack of assurance about its own. (For that matter, given what little we know at this stage in the proceedings, Mr. Fikre may have done none of the things the government presumes he has, perhaps wishing to but refraining for fear of finding himself relisted.)”

Justice Samuel Alito and Justice Brett Kavanaugh, both conservatives, clarified in a separate letter that the government need not provide Fikre with access to classified material to demonstrate that his case is without merit.

“In at least some instances, requiring the Government to disclose sensitive information regarding its grounds for placing or removing a person from the No-Fly List could undermine the Government’s significant interests in airline safety and the prevention of terrorist attack,” Alito wrote.

Fikre’s attorneys, Lindsay Harrison and Annie Kastanek, partners at Jenner & Block, praised the decision.

“We are proud to have helped Mr. Fikre secure justice through this unanimous US Supreme Court decision,” they said in a statement.

“Mr. Fikre was unconstitutionally placed on the No Fly List and stranded overseas for four years, and today’s victory underscores that the government cannot evade review of its national security policies by selectively mooting out cases,” they added.