As legal weed becomes a reality in every corner of the U.S., Idaho is putting up a fight.

State lawmakers on Friday moved forward with a proposed constitutional amendment that would bar the legalization of marijuana in Idaho in an attempt to keep the growing nationwide acceptance of the drug from seeping across its borders.

Idaho is one of only three states without some sort of policy allowing residents to possess products with even low amounts of THC, the psychoactive chemical in marijuana. Residents can cross the state border in nearly every direction and find themselves in a place where marijuana can be bought for recreational or medicinal purposes. Support for medicinal marijuana use is growing among some residents — with legalization activists trying to get an initiative on the state ballot in 2022.

It’s made some lawmakers in the deep-red state nervous, particularly after voters in the neighboring state of Oregon decriminalized the personal possession of drugs like heroin, cocaine and methamphetamine last November.

The joint resolution to ban all psychoactive drugs not already legal in Idaho won approval along a 6-2 party-line vote in the Senate State Affairs Committee. The list of substances would change for drugs approved by the Food and Drug Administration. [Read more at ABC News]