The 10th Circuit Court of Appeals on Thursday reversed a district court preliminary injunction that could have paved the way for spontaneous protests at Denver International Airport.

Demonstrators protesting the Trump administration’s travel ban gathered at DIA Jan. 28 and 29, 2017, and were confronted by Denver police, who warned they could be arrested for demonstrating at the airport without a permit.

A lawsuit was filed on behalf of the protesters, including Nazli McDonnell and Eric Verlos, alleging that their First and 14th amendment rights were violated.

On Thursday, the court of appeals reversed a Feb. 22, 2017, U.S. District Court ruling that had granted an injunction in favor of the plaintiffs.

In coming to the reversal, the appeals court, in part, cited revised municipal codes pertaining to the airport, including “regulation 50,” which regulates “all leafleting, display of signs, signature gathering, solicitations of funds and other speech related activity conducted at Denver International Airport for religious, charitable, or political purposes, or in connection with labor disputes.”

Regulation 50 states that potential protesters at DIA submit an application seven days in advance of an event to obtain a permit, which, if granted, would regulate where and when protesters would gather on airport grounds.

Thursday’s reversal allows DIA, the city and Denver police to enforce restrictions on picketing and protesting at the airport and to exercise “discretion to select the location of a permitted protest” at the airport.

“We are pleased that the court’s decision recognizes that an international airport is a unique operating environment with special considerations that are not the same as a street or other venue,” airport spokesman Heath Montgomery wrote in an email Friday morning. “The airport has longstanding rules, which have and will continue to balance free speech activities with the need to protect the airport’s core operations and the safety and security of its passengers.”

The Jan. 28 protest against the Trump travel ban was held inside the Great Hall, and the subsequent protest was held in a courtyard area between the south end of the terminal and the Westin Denver International Airport hotel.

David Lane, an attorney for the plaintiffs, described the reversal as disappointing.

“Basically, they said you can’t have a spontaneous demonstration in the Great Hall at DIA because it is not a traditional public forum. Therefore Denver and DIA can put restrictions on it,” Lane said. “I think that’s a shame because every time the courts close down an avenue of protests to the people, we become a little less of a free society.”

Lane said the second-day protest last year was steered to the courtyard because it’s less visible.

“The upshot is the protest loses its force,” Lane said.

The reversal also cited a U.S. Supreme Court ruling upholding bans on face-to-face solicitation at airports because such actions are “incompatible with the airport’s functioning” where travelers, with luggage and facing time constraints, would face congestion and interference.

UPDATE: This story was updated at 11 a.m. Friday to include comments from the airport.