diff --git a/keystone_tempest_plugin/clients.py b/keystone_tempest_plugin/clients.py
index 9865b91..97b5b14 100644
--- a/keystone_tempest_plugin/clients.py
+++ b/keystone_tempest_plugin/clients.py
@@ -26,8 +26,8 @@
 
 class Manager(clients.Manager):
 
-    def __init__(self, credentials, service=None):
-        super(Manager, self).__init__(credentials, service)
+    def __init__(self, credentials):
+        super(Manager, self).__init__(credentials)
 
         self.auth_client = auth_client.AuthClient(self.auth_provider)
         self.identity_providers_client = (
diff --git a/keystone_tempest_plugin/tests/base.py b/keystone_tempest_plugin/tests/base.py
index 83f5c12..6ba6659 100644
--- a/keystone_tempest_plugin/tests/base.py
+++ b/keystone_tempest_plugin/tests/base.py
@@ -32,7 +32,7 @@
         super(BaseIdentityTest, cls).setup_clients()
         credentials = common_creds.get_configured_admin_credentials(
             cls.credential_type, identity_version=cls.identity_version)
-        cls.keystone_manager = clients.Manager(credentials=credentials)
+        cls.keystone_manager = clients.Manager(credentials)
         cls.auth_client = cls.keystone_manager.auth_client
         cls.idps_client = cls.keystone_manager.identity_providers_client
         cls.mappings_client = cls.keystone_manager.mapping_rules_client