diff --git a/web/server/codechecker_server/session_manager.py b/web/server/codechecker_server/session_manager.py
index 2bcae3cbc9..282aad627b 100644
--- a/web/server/codechecker_server/session_manager.py
+++ b/web/server/codechecker_server/session_manager.py
@@ -539,6 +539,9 @@ def get_db_auth_session_tokens(self, user_name):
 
     def __is_root_user(self, user_name):
         """ Return True if the given user has system permissions. """
+        if 'super_user' not in self.__auth_config:
+            return False
+
         if self.__auth_config['super_user'] == user_name:
             return True