On Tuesday, the Supreme Court ruled unanimously against private prison company Geo Group, denying them a fast-track appeal of a lower court ruling that found they are not immune from being sued.

The initial lawsuit was brought about in 2014 by Alejandro Menocal and other former detainees at the Aurora Immigration Processing Center in Colorado. They filed a class action lawsuit against GEO Group claiming they were forced to clean common areas and were punished with solitary confinement if they said no. Detainees claimed that they worked at the detention center for either $1 a day or no pay at all.

Geo Group, the second-largest contractor for President Trump’s mass detention campaign, didn’t think it should even be able to be sued in the first place.

The prison company argued that it deserved “derivative sovereign immunity,” something usually reserved for the government, because it works with and for the U.S. government. It also claimed that it should have the right to immediate appeals rather than after-trial appeals, which would have allowed it to ignore unfavorable rulings.

Now, thanks to the unanimous Supreme Court ruling, the forced-labor lawsuit brought by the immigrant detainees at Geo Group can move forward.