Tennessee is going to expand its use of the electric chair, making electrocution the state’s method of execution if lethal injection is not available.

The new law, signed by Gov. Bill Haslam (R) on Thursday night, allows the state to execute inmates in the electric chair if lethal injection is deemed unconstitutional or if the execution drugs can’t be obtained.

Lethal injection remains Tennessee’s default way to execute inmates sentenced to death. But as states face drug shortages and worry about potential court challenges, they are looking at other ways to execute inmates. While some states have flirted with the idea of reviving firing squads and others have contemplated gas chambers, none has actually adopted any of these methods.

Tennessee is the first state since the drug shortage began to approve an alternative to lethal injection that would be used without the inmate having any choice. The new law covers any inmate who commits a crime on or after July 1.

This has been widely reported as Tennessee “bringing back the electric chair,” which isn’t technically accurate. The electric chair has long been an option for certain executions in Tennessee, which is one of eight states that allows electrocutions under specific circumstances. The new law, rather than reviving a discarded method, expands the potential use of the electric chair and could remove choice from the equation.

Since 2000, inmates in Tennessee who committed crimes before Jan. 1, 1999, could choose between lethal injection and electrocution, according to the Tennessee Department of Correction.

The state last executed an inmate using the electric chair in 2007. Daryl Holton, who had killed his three sons and their half-sister a decade earlier, was put to death with two jolts of electricity. Since the Supreme Court reinstated capital punishment in 1976, there have been 158 executions carried out through electrocution (the last one was in Virginia last year). That’s a small fraction of the 1,379 executions that have been carried out over that span, as the majority all of the executions have been lethal injections.

Along with Tennessee, seven other states still allow electrocution: Alabama, Arkansas, Florida, Kentucky, Oklahoma, South Carolina and Virginia. Lethal injection is the primary method of execution in these states (as well as in every state that still has the death penalty), but the rules governing the electric chair vary from state to state. In Florida and Virginia, for example, prisoners can choose between electrocution or lethal injection; in Oklahoma, if lethal injection is ever deemed unconstitutional, electrocution can be used. Kentucky allows people who committed crimes before March 31, 1998, to select between lethal injection or electrocution.

In addition to electrocutions and lethal injections, eight states also allow for other methods of execution. Three states allow the gas chamber (Arizona, Missouri and Wyoming), three others allow hanging (Delaware, New Hampshire and Washington) and two states allow firing squads (Oklahoma and Utah). Again, these are not the default methods, and the circumstances under which they can be used vary from state to state. Oklahoma allows the firing squad if lethal injection and electrocution are both deemed unconstitutional, while Arizona allows for the gas chamber for people sentenced before Nov. 15, 1992.

Here’s a useful visualization showing what methods are available across the country.

Tennessee has executed six inmates since the death penalty was reinstated in 1976, according to the Death Penalty Information Center. The state last carried out an execution in 2009.