State regulators said that a misreading of the law that legalized cannabis in New York allowed some shops to open in unsuitable locations. Those businesses may be uprooted now.

New York’s budding cannabis industry just got smoked by a math mistake. Dozens of cannabis dispensaries across New York are facing the possibility of relocation—or closure—after state officials admitted to miscalculating how close shops were to nearby schools.

Lawmakers are scrambling to protect more than 150 cannabis retail shops whose operators were informed this week that their stores are too close to schools.