The U..S Court of Appeals in the 7th Circuit ruled Tuesday(April 4) that because the Civil Rights Act of 1964 protects people from sex discrimination, it also applies to those facing anti-gay and -lesbian bias. The case in question centers on Kimberly Hively, a teacher who believed that Indiana’s Ivy Tech Community College repeatedly denied her full-time employment and then fired from her part-time position because she’s a lesbian.

The logic of the ruling is that anti-gay discrimination is actually rooted in sex discrimination. Vox explains:

For example, if someone discriminates against a gay man, that’s largely based on the expectation that a man should only love or have sex with a woman — a belief built on the idea of what a person of a certain sex should be like. Similarly, if someone discriminates against a trans woman, that’s largely based on the expectation that a person designated male at birth should identify as a man — again, a belief built on the idea of what a person of a certain sex assigned at birth should be like.

The Hively v. Ivy Tech Community College ruling is a major advancement in LGBTQ rights. It could be on par with the marriage decision in 2015, but, so far, it only applies to states governed by the 7th Circuit, Indiana, Illinois and Wisconsin. If the case reaches the U.S. Supreme Court, that decision would either extend the ruling nationwide or reverse it altogether. A nationwide extension of Tuesday’s Hively ruling could be of particular benefit to LGBTQ people of color since many live in Southern states with little chance of passing anti-discrimination laws. Twenty eight states have no such laws, including most of the South and Midwest.