diff --git a/kallithea/lib/auth_modules/auth_container.py b/kallithea/lib/auth_modules/auth_container.py
--- a/kallithea/lib/auth_modules/auth_container.py
+++ b/kallithea/lib/auth_modules/auth_container.py
@@ -27,7 +27,7 @@ Original author and date, and relevant c
 
 import logging
 from kallithea.lib import auth_modules
-from kallithea.lib.utils2 import str2bool, safe_unicode
+from kallithea.lib.utils2 import str2bool, safe_unicode, safe_str
 from kallithea.lib.compat import hybrid_property
 from kallithea.model.db import User, Setting
 
@@ -182,7 +182,7 @@ class KallitheaAuthPlugin(auth_modules.K
         # only way to log in is using environ
         username = None
         if userobj:
-            username = getattr(userobj, 'username')
+            username = safe_str(getattr(userobj, 'username'))
 
         if not username:
             # we don't have any objects in DB, user doesn't exist, extract