The U.S. Senate on March 17 unanimously passed a bill that would make crucial changes to current cocaine sentencing laws.

The Fair Sentencing Act was originally introduced by Sen. Richard Durbin (D-Ill.) to correct a current 100-1 disparity between crack and powder cocaine sentencing under federal law.

During the bill’s markup last week, a compromise was reached with Republican Judiciary Committee members which reduced the disparity to a 18-1 ratio. A House version of the bill was passed by the House Judiciary Committee last year and is currently awaiting a vote by the full chamber. A combined version of the bill would have to be agreed upon before new laws go into effect.

“Drug use is a serious problem in America and we need tough legislation to combat it,” Durbin said in a statement. “But in addition to being tough, our drug laws must be smart and fair. Our current cocaine laws are not.”

Over two decades ago, heightened penalties for crack were enacted based on claims—now proven false—that crack is more addictive than powder cocaine. Currently, sentences for crack are the equivalent to the sentences for 100 times the amount of powder cocaine and the effect falls disproportionately on Blacks.

The American Civil Liberties Union said it believes the bill is a step in the right direction, but that the sentencing system is still unjust with an 18-1 ratio.

“The Fair Sentencing Act is an encouraging step toward eliminating the sentencing disparity between crack and powder cocaine but still allows for a needlessly unfair sentencing framework,” Laura W. Murphy, director of the ACLU Washington Legislative Office, said in a press release. “The unanimous passage of this bill speaks to the understanding across the political spectrum that this disparity is unjust and in need of reform. Years of research has yielded no evidence of any appreciable difference between crack and powder cocaine and yet we continue to inflict this disparity on Americans.”

The NAACP is also strongly opposed to the mandatory minimum for crack cocaine possession. The organization spoke out against the inequality of crack cocaine sentencing and powder cocaine sentencing in 2007, when then-Attorney General Michael Mukasey called for Congress to overrule a reduction in the mandatory minimum sentences for crack.

“The crack/powder cocaine sentencing disparity continues to place more African-Americans and Latinos behind bars for much longer periods of time, despite the fact that the two drugs are pharmacologically indistinguishable,” Hilary Shelton, Washington Bureau director of the NAACP, said in a statement. “For over two decades, this sentencing disparity has been a stain on our justice system.”