diff --git a/modules/ui.py b/modules/ui.py
index f48638f69..9a76b5fcd 100644
--- a/modules/ui.py
+++ b/modules/ui.py
@@ -44,6 +44,9 @@ mimetypes.add_type('application/javascript', '.mjs')
 mimetypes.add_type('image/webp', '.webp')
 mimetypes.add_type('image/avif', '.avif')
 
+# override potentially incorrect mimetypes
+mimetypes.add_type('text/css', '.css')
+
 if not cmd_opts.share and not cmd_opts.listen:
     # fix gradio phoning home
     gradio.utils.version_check = lambda: None