diff --git a/atst/assets.py b/atst/assets.py
index 6d8351a6..aaf1f82e 100644
--- a/atst/assets.py
+++ b/atst/assets.py
@@ -4,7 +4,7 @@ environment = Environment()
 
 css = Bundle(
     "../static/assets/index.css",
-    output="../static/assets/styles.%(version)s.css",
+    output="../static/assets/index.%(version)s.css",
 )
 
 environment.register("css", css)