diff --git a/ydb/tests/library/harness/kikimr_config.py b/ydb/tests/library/harness/kikimr_config.py
index c7c31acf77a3..5a8c3a680758 100644
--- a/ydb/tests/library/harness/kikimr_config.py
+++ b/ydb/tests/library/harness/kikimr_config.py
@@ -331,9 +331,6 @@ def __init__(
 
         if auth_config_path:
             self.yaml_config["auth_config"] = _load_yaml_config(auth_config_path)
-        else:
-            self.yaml_config['auth_config'] = {}
-        self.yaml_config['auth_config']['use_builtin_domain'] = True
 
         if fq_config_path:
             self.yaml_config["federated_query_config"] = _load_yaml_config(fq_config_path)