diff --git a/ironic/api/controllers/v1/types.py b/ironic/api/controllers/v1/types.py
index 482e993264..f1f24e1670 100644
--- a/ironic/api/controllers/v1/types.py
+++ b/ironic/api/controllers/v1/types.py
@@ -117,7 +117,7 @@ class BooleanType(wtypes.UserType):
             return strutils.bool_from_string(value, strict=True)
         except ValueError as e:
             # raise Invalid to return 400 (BadRequest) in the API
-            raise exception.Invalid(e)
+            raise exception.Invalid(six.text_type(e))
 
     @staticmethod
     def frombasetype(value):
diff --git a/ironic_tempest_plugin/clients.py b/ironic_tempest_plugin/clients.py
index 8ec1db6655..c491c7759d 100644
--- a/ironic_tempest_plugin/clients.py
+++ b/ironic_tempest_plugin/clients.py
@@ -27,15 +27,13 @@ ADMIN_CREDS = common_creds.get_configured_admin_credentials()
 
 class Manager(clients.Manager):
     def __init__(self,
-                 credentials=ADMIN_CREDS,
-                 service=None):
+                 credentials=ADMIN_CREDS):
         """Initialization of Manager class.
 
         Setup service client and make it available for test cases.
         :param credentials: type Credentials or TestResources
-        :param service: service name
         """
-        super(Manager, self).__init__(credentials, service)
+        super(Manager, self).__init__(credentials)
         default_params_with_timeout_values = {
             'build_interval': CONF.compute.build_interval,
             'build_timeout': CONF.compute.build_timeout