Feldstein walked the red carpet in a black Kay Unger gown, which — wait for it — the actress told The Cut last week, is her prom dress from high school. “I put it on and it fit, surprisingly maybe better than it did in high school! I looked at myself and I was like, WHAT!? and my mom and her best friend were just laughing so hard, like, ‘You have to wear it! There’s just no other dress that would be better,’” she explained. Feldstein looked at it as a chance to pay tribute to the power of Lady Bird. “It’s just a gorgeous dress, and I love how my character’s story ends at the prom, so like, for the first time I’m going to an awards show as a nominee with the cast, it’s like, you gotta wear your prom dress, girl, and honor Julie.”