The Department of Transportation could soon institute new rules that limit what service animals will be allowed on commercial aircraft. Under a proposal announced Wednesday, only professionally trained dogs would be allowed to accompany people during flights.

In a statement, the Airlines for America industry group voiced support for the proposal and said that it would promote safety for all passengers during air travel.

“Airlines are committed to promoting accessibility for passengers with disabilities and ensuring their safe and successful travel,” the statement read. “The DOT's decision to limit its definition of ‘service animal’ to include only dogs trained to do work or perform tasks for the benefit of an individual with a disability is a positive step in protecting the legitimate right of passengers to travel with a service animal.”

The proposal would also end rules requiring airlines to accept many varieties of emotional support animals. While airlines would be allowed to accept any sort of animal at their own discretion, they would now be required to undergo training similar to that of service animals for the disabled.

“Untrained pets should never roam free in the aircraft cabin,” the Association of Flight Attendants said in a statement to the New York Times. “The days of Noah’s Ark in the air are hopefully coming to an end.”

The topic of emotional support animals on commercial flights has flared up in recent years in the wake of numerous stories of bizarre animals brought onto flights. Notably, in January 2018, a woman flying out of Newark attempted to bring a peacock onto a United Airlines flight as an emotional support animal.

Chicago, Illinois-based United Airlines, which has flights to airports around the globe, is one of the world's largest airlines based on fleet size
Chicago, Illinois-based United Airlines, which has flights to airports around the globe, is one of the world's largest airlines based on fleet size GETTY IMAGES NORTH AMERICA / JUSTIN SULLIVAN