Amtrak is tightening its recent face mask requirement.

The passenger railroad began requiring customers to wear a mask or facial covering in May to protect against the spread of the coronavirus, but guidelines on its website now say Amtrak “reserves the right to remove customers or ban them from future travel in the event of noncompliance.”

The update came Thursday, according to USA Today. When asked how Amtrak would enforce its requirement in May, Amtrak spokesperson Beth Toll said that customers were to supply their own facial coverings and that service would be denied to those who weren’t adhering to the policy.

Reached for comment Friday, Toll did not confirm when the update was made, or clarify why it strengthened the requirement.

“As part of Amtrak’s ongoing commitment to protect customers and front-line employees in response to the coronavirus pandemic, Amtrak is requiring that all customers in stations, on trains and thruway buses wear face masks,” Amtrak said in a statement. “Face masks can be removed when customers are in their private rooms. Small children who are not able to maintain a face covering are exempt from this requirement.”

Amtrak previously said riders could remove coverings when “eating in designated areas, in their private rooms, or seated alone or with a travel companion in their own pair of seats.”

The facial covering requirement joins other steps Amtrak has taken to mitigate the virus’ spread, including enhanced cleaning as well as limiting bookings.

Amtrak’s intent to ban passengers is akin to policies put into place by airlines rather than public transit agencies. More than 100 people were barred from flying Delta for refusing to wear a mask, according to the Hill. United and American Airlines customers could be temporarily banned from flying under similar rules.

SEPTA began requiring riders to wear facial coverings last month, but General Manager Leslie S. Richards said the policy would not be enforced by transit police. Reminders are posted on vehicles and at station platforms. The authority ramped up a social media campaign promoting mask wearing in June as it continues to see a slow rise in ridership.

SEPTA faced backlash in April over a viral video that showed a man dragged off a bus allegedly for not wearing a facial covering.

PATCO began requiring face coverings this month. Riders who don’t “may be denied entry to or asked to leave PATCO premises,” according to a news release.