The first known transgender rights lawsuit alleging Americans with Disabilities Act discrimination based on the condition of gender dysphoria can move forward, a federal judge has ruled.

U.S. District Judge Joseph F. Leeson’s opinion denying outdoor retailer Cabela’s motion to dismiss the ADA portion of Kate Lynn Blatt’s lawsuit comes nearly a year-and-a-half after argument was heard on the issue, in December 2015. Transgender rights advocates are calling the ruling a significant step forward in transgender legal protections.