diff --git a/vcsserver/git_lfs/app.py b/vcsserver/git_lfs/app.py
--- a/vcsserver/git_lfs/app.py
+++ b/vcsserver/git_lfs/app.py
@@ -60,6 +60,7 @@ class AuthHeaderRequired:
         request = fargs[1]
         auth = request.authorization
         if not auth:
+            log.debug('No auth header found, returning 403')
             return write_response_error(HTTPForbidden)
         return func(*fargs[1:], **fkwargs)