The Education Department is investigating whether Denver Public Schools committed discrimination when its largest high school converted the second floor’s only girls’ restroom into a multi-stall, all-gender bathroom while leaving the boys’ restroom on that floor intact.

The U.S. Department of Education’s Office for Civil Rights will open an investigation into Denver Public Schools for “discriminating against its female students” by creating an all-gender bathroom at East High School,

The department says the change violates Title IX because it impacts the rights of female students at the school.