diff --git a/ydb/core/external_sources/object_storage.cpp b/ydb/core/external_sources/object_storage.cpp
index 1a9f3187ac5e..8710865e3ec8 100644
--- a/ydb/core/external_sources/object_storage.cpp
+++ b/ydb/core/external_sources/object_storage.cpp
@@ -303,6 +303,8 @@ struct TObjectStorageExternalSource : public IExternalSource {
             }
             auto& saAuth = std::get<NAuth::TServiceAccount>(meta->Auth);
             structuredTokenBuilder.SetServiceAccountIdAuth(saAuth.ServiceAccountId, saAuth.ServiceAccountIdSignature);
+        } else {
+            structuredTokenBuilder.SetNoAuth();
         }
 
         const NYql::TS3Credentials credentials(CredentialsFactory, structuredTokenBuilder.ToJson());