Nebraska and Oklahoma recently set out to declare Colorado’s pot legalization unconstitutional, but it looks like the Supreme Court has rejected it.

The two states had originally argued that Colorado’s recreational marijuana law violates federal anti-drug laws. They also claimed the legalization in Colorado is negatively affecting their own drug policies, as it’s quickly making its way over the Colorado border.

While the Obama Administration is not necessarily for the legalization of marijuana, they did side with Colorado on this one.

So far, Colorado, Oregon, Alaska, Washington state, and Washington D.C. have all legalized recreational use for adults, and 23 states allow medical use. Still, marijuana is considered an illegal drug at the federal level.

The justices are not commenting today on the decision. Legal marijuana sales are predicted to hit $23B by 2020.