Colleges in states where medical marijuana is legal are telling students the drug is not allowed on campus, even if they have a doctor’s recommendation.

College administrators say their policies must follow federal regulations, which classify marijuana as an illegal drug, according to The Boston Globe. Administrators are concerned marijuana use of any kind could lead to loss of federal funding, including student financial aid, the article notes. Consequences for marijuana use on campuses range from warnings to expulsions.

Medical marijuana advocates and patients call the campus bans unfair to students and faculty who use the drug to treat illnesses. Advocates say they do not believe the government would cut off funding to colleges that allow the use of medical marijuana.

In Massachusetts, some colleges that ban medical marijuana are trying to help students with doctors’ recommendations to find alternatives, such as living off-campus. Boston University Dean of Students Kenneth Elmore told the newspaper a few students with medical marijuana certifications have asked whether they can use the drug on campus. Elmore said they cannot. “We don’t make a distinction between medical and recreational marijuana,” he said. “We simply don’t allow marijuana on our campus. Federally, it is illegal, and smoking causes disruptions on campus.”

Several Massachusetts colleges say they are considering revising their medical marijuana policies. “It is unclear what impact, if any, a change in policy would have on federal funding,” said Jeffrey Kirksey, Vice President for Student Development and Retention at Eastern Nazarene College.

In 2011, the White House Office of National Drug Control Policy (ONDCP) and the Education Department said campuses that deviate from federal rules on marijuana could put their federal funding at risk. “The administration’s stance hasn’t changed since then,” ONDCP spokeswoman Cameron Hardesty told the newspaper.