diff --git a/py/visdom/utils/server_utils.py b/py/visdom/utils/server_utils.py
index fb7f0415d..cc6962bbd 100644
--- a/py/visdom/utils/server_utils.py
+++ b/py/visdom/utils/server_utils.py
@@ -53,8 +53,9 @@ def _check_auth(handler, *args, **kwargs):
         # TODO this should call a shared method of the handler
         handler.last_access = time.time()
         if handler.login_enabled and not handler.current_user:
-            handler.set_status(400)
-            return
+           handler.set_status(401)
+           handler.write({"error": "Authentication required"})
+           return
         f(handler, *args, **kwargs)
 
     return _check_auth