Leaders of Oakland, California, unanimously approved a resolution on Tuesday to decriminalize psilocybin and other “natural sources” of psychedelics.

With the vote, Oakland becomes the second U.S. city to decriminalize psilocybin, the psychoactive substance in “magic mushrooms,” after voters in Denver narrowly approved a similar citizen initiative in May.

The Oakland City Council’s public safety committee held a public hearing on the resolution on May 28 before sending it to the full council for a vote. Council members voted to approve the measure, which directs local law enforcement to stop investigating and prosecuting people for possession and use of certain psychedelic substances.

In addition to psilocybin, the measure also decriminalizes ayahuasca, peyote and ibogaine. It will not protect the use and possession of synthetic drugs like LSD or MDMA.

Activists behind the initiative say plant-based entheogens ― a term that describes psychedelic substances believed to induce spiritual experiences ― may help reduce symptoms of certain mental health issues.

“Substance abuse, addiction, recidivism, trauma, post-traumatic stress symptoms, chronic depression, severe anxiety, end-of-life anxiety, grief, diabetes, cluster headaches, and other conditions are plaguing our community,” reads the resolution drafted by Decriminalize Nature Oakland, a community group advocating for the decriminalization of natural psychedelics.

It continues: “The use of Entheogenic Plants have been shown to be beneficial to the health and well-being of individuals and communities in addressing these afflictions.”

Advocates also argue that indigenous groups have used psilocybin and other hallucinogenic plants for centuries.

The federal government classifies psilocybin as a Schedule I drug, which means it’s legally considered to have no medical purpose and a high potential for abuse. The substance has been outlawed in the U.S. since the 1960s.