A bill that would allow Idaho to execute condemned inmates by firing squad is headed to the governor’s desk after passing the Legislature on Monday with a veto-proof majority.

Firing squads will be used only if the state cannot obtain the drugs needed for lethal injections — but one death row inmate has already had his scheduled execution postponed multiple times because of drug scarcity.

Idaho previously had a firing squad option on the books but has never used it. The option was removed it from state law in 2009 after the U.S. Supreme Court upheld a method of lethal injection that was commonly used at the time.

Only Mississippi, Utah, Oklahoma and South Carolina currently have laws allowing firing squads if other execution methods are unavailable, according to the Death Penalty Information Center. A judge has put South Carolina’s law on hold until a lawsuit challenging the method is resolved.