Delta Airlines said Monday that it will ban all emotional-support animals on flights longer than eight hours and will ban all service and support animals under four months of age on flights no matter the duration. The policy will go into effect Dec. 18, ahead of the Christmas holiday travel season.

“These updates support Delta’s commitment to safety and also protect the rights of customers with documented needs — such as veterans with disabilities — to travel with trained service and support animals,” said John Laughter, Delta’s senior vice president for corporate safety, security and compliance.