(CNN) Denver has approved a city ordinance to decriminalize hallucinogenic mushrooms, the city's elections division said.

The Initiated Ordinance 301, or the Denver Psilocybin Mushroom Initiative , was approved Tuesday by less than 2,000 votes, according to preliminary results from the elections division.

About 50.5% of voters supported the ordinance, while about 49.4% were against it, election officials said.

The results will not become official until May 16.

The ordinance's text seeks to "deprioritize, to the greatest extent possible" criminal penalties imposed by the City of Denver "for the personal use and personal possession of psilocybin mushrooms."

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