Sen. Jeff Merkley (D-Ore.) and Rep. Wm. Lacy Clay (D-Mo.) proposed a joint resolution Wednesday to remove a punitive provision in the 13th Amendment of the Constitution, which outlaws slavery.

The resolution calls for the House and Senate to craft an amendment saying that “neither slavery nor involuntary servitude may be imposed as a punishment for a crime.”

The lawmakers said the wording would close a loophole in the 13th Amendment that still provides an avenue for slavery to be legal. The amendment currently reads that “neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.”

“America was founded on beautiful principles of equality and justice and horrific realities of slavery and white supremacy, and if we are ever going to fully deliver on the principles we have to directly confront the realities,” said Merkley. “The exception to the 13th Amendment’s ban on slavery corrupted criminal justice into a tool of racist control of Black Americans and other people of color, and we see that legacy every day in police encounters, courtrooms, and prisons throughout our country. Slavery is incompatible with justice. No slavery, no exceptions.”

“Our Abolition Amendment seeks to finish the job that President Lincoln started by ending the punishment clause in the 13th Amendment to eliminate the dehumanizing and discriminatory forced labor of prisoners for profit that has been used to drive the over-incarceration of African Americans since the end of the Civil War. No American should ever be subject to involuntary servitude, even if they are incarcerated,” added Clay.

Merkley and Clay were joined by 17 co-sponsors in introducing the legislation. 

In a statement announcing the legislation, Merkley and Clay tied the loophole to “Black Codes” that were implemented in the late 1800s and used by Southern sheriffs to lease out imprisoned people to work landowners’ fields. Merkley and Clay said the language created “a financial incentive for mass incarceration” that they say still exists today in unequal treatment of people of color in the criminal justice system.