On March 15, 2024, the Drug Enforcement Administration published a final order placing 1-(2-methyl-4-(3-phenylprop-2-en-1- yl)piperazin-1-yl)butan-1-one (commonly known as 2-methyl AP-237), including its optical and geometric isomers, esters, ethers, salts, and salts of isomers, esters, and ethers whenever the existence of such isomers, esters, ethers, and salts is possible within the specific chemical designation, in schedule I of the Controlled Substances Act. The effective date of that final order was 30 days after publication in the Federal Register. Before the effective date, DEA published another final order that made the instructions for 2-methyl AP-237 in the March 15 final order invalid. This document corrects that error, adding 2- methyl AP-237 and its drug code 9664 for regulatory purposes.