SEATTLE (AP) — Greyhound, the nation’s largest bus company, said Friday it will stop allowing Border Patrol agents without a warrant to board its buses to conduct routine immigration checks.

The company’s announcement came one week after The Associated Press reported on a leaked Border Patrol memo confirming that agents can’t board private buses without the consent of the bus company. Greyhound had previously insisted that even though it didn’t like the immigration checks, it had no choice under federal law but to allow them.

In an emailed statement, the company said it would notify the Department of Homeland Security that it does not consent to unwarranted searches on its buses or in areas of terminals that are not open to the general public. It said it would provide its drivers and bus station employees updated training regarding the new policy, and that it would place stickers on all its buses clearly stating that it does not consent to the searches.

Greyhound has faced pressure from the American Civil Liberties Union, immigrant rights activists and Washington state Attorney General Bob Ferguson to stop allowing sweeps on buses within 100 miles (160 kilometers) of an international border or coastline.

They say the practice is intimidating and discriminatory and has become more common under President Donald Trump. Border Patrol arrests videotaped by other passengers have sparked criticism, and Greyhound faces a lawsuit in California alleging that it violated consumer protection laws by facilitating raids.

Some other bus companies, including Jefferson Lines, which operates in 14 states, and MTRWestern, which operates in the Pacific Northwest, have made clear that they do not consent to agents boarding buses.

The memo obtained by the AP was dated Jan. 28, addressed to all chief patrol agents and signed by then-Border Patrol Chief Carla Provost just before she retired. It confirms the legal position that Greyhound’s critics have taken: that the Constitution’s Fourth Amendment prevents agents from boarding buses and questioning passengers without a warrant or the consent of the company.

“When transportation checks occur on a bus at non-checkpoint locations, the agent must demonstrate that he or she gained access to the bus with the consent of the company’s owner or one of the company’s employees,” the memo states. An agent’s actions while on the bus “would not cause a reasonable person to believe that he or she is unable to terminate the encounter with the agent.”