WASHINGTON (AP) — President Donald Trump’s acting attorney general on Thursday signed an order reclassifying state-licensed medical marijuana as a less-dangerous drug, a major policy shift long sought by advocates who said cannabis should never have been treated like heroin by the federal government.

The order signed by Todd Blanche does not legalize marijuana for medical or recreational use under federal law. But it does change the way it’s regulated, shifting licensed medical marijuana from Schedule I — reserved for drugs without medical use and with high potential for abuse — to the less strictly regulated Schedule III. It also gives licensed medical marijuana operators a major tax break and eases some barriers to researching cannabis.

It makes clear that cannabis researchers won’t be penalized for obtaining state-licensed marijuana or marijuana-derived products for use in their work, and it grants state-licensed medical marijuana companies a windfall by allowing them, for the first time, to deduct business expenses on their federal taxes.

Trump told his administration in December to work as quickly as possible to reclassify marijuana. On Saturday, as the Republican president signed an unrelated executive order about psychedelics, he seemed to express frustration that it was taking so long.

Many Republicans oppose loosening marijuana restrictions. More than 20 Republican senators, several of them staunch Trump allies, signed a letter last year urging the president to keep the current standards.

Two dozen states plus Washington, D.C., have authorized adult recreational use of marijuana, 40 have medical marijuana systems, and eight others allow low-THC cannabis or CBD oil for medical use. Only Idaho and Kansas ban marijuana outright.

The administration also said it was starting the process for reclassifying marijuana more broadly, setting a hearing for late June.