diff --git a/tempest/api/object_storage/base.py b/tempest/api/object_storage/base.py
index 11273e4594..4c49b2a4d9 100644
--- a/tempest/api/object_storage/base.py
+++ b/tempest/api/object_storage/base.py
@@ -71,9 +71,6 @@ class BaseObjectTest(tempest.test.BaseTestCase):
     def setup_credentials(cls):
         cls.set_network_resources()
         super(BaseObjectTest, cls).setup_credentials()
-        # credentials may be overwritten by children classes
-        if hasattr(cls, 'os_roles_operator'):
-            cls.os = cls.os_roles_operator
 
     @classmethod
     def setup_clients(cls):
diff --git a/tempest/api/object_storage/test_account_quotas.py b/tempest/api/object_storage/test_account_quotas.py
index 092d36969d..f46c2564f3 100644
--- a/tempest/api/object_storage/test_account_quotas.py
+++ b/tempest/api/object_storage/test_account_quotas.py
@@ -29,7 +29,6 @@ class AccountQuotasTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(AccountQuotasTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_reselleradmin = cls.os_roles_reseller
 
     @classmethod
diff --git a/tempest/api/object_storage/test_account_quotas_negative.py b/tempest/api/object_storage/test_account_quotas_negative.py
index 60233b4422..431bbe9a83 100644
--- a/tempest/api/object_storage/test_account_quotas_negative.py
+++ b/tempest/api/object_storage/test_account_quotas_negative.py
@@ -29,7 +29,6 @@ class AccountQuotasNegativeTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(AccountQuotasNegativeTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_reselleradmin = cls.os_roles_reseller
 
     @classmethod
diff --git a/tempest/api/object_storage/test_account_services.py b/tempest/api/object_storage/test_account_services.py
index 2fb676fe39..65cebb37de 100644
--- a/tempest/api/object_storage/test_account_services.py
+++ b/tempest/api/object_storage/test_account_services.py
@@ -36,7 +36,6 @@ class AccountTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(AccountTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_operator = cls.os_roles_operator_alt
 
     @classmethod
diff --git a/tempest/api/object_storage/test_account_services_negative.py b/tempest/api/object_storage/test_account_services_negative.py
index e98a4f540e..3e664d74a3 100644
--- a/tempest/api/object_storage/test_account_services_negative.py
+++ b/tempest/api/object_storage/test_account_services_negative.py
@@ -28,7 +28,6 @@ class AccountNegativeTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(AccountNegativeTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_operator = cls.os_roles_operator_alt
 
     @decorators.attr(type=['negative'])
diff --git a/tempest/api/object_storage/test_container_acl_negative.py b/tempest/api/object_storage/test_container_acl_negative.py
index 655626c293..e064753ca1 100644
--- a/tempest/api/object_storage/test_container_acl_negative.py
+++ b/tempest/api/object_storage/test_container_acl_negative.py
@@ -29,7 +29,6 @@ class ObjectACLsNegativeTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(ObjectACLsNegativeTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_operator = cls.os_roles_operator_alt
 
     @classmethod
diff --git a/tempest/api/object_storage/test_container_sync.py b/tempest/api/object_storage/test_container_sync.py
index 4cb1914047..7665b48855 100644
--- a/tempest/api/object_storage/test_container_sync.py
+++ b/tempest/api/object_storage/test_container_sync.py
@@ -41,7 +41,6 @@ class ContainerSyncTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(ContainerSyncTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_alt = cls.os_roles_operator_alt
 
     @classmethod
diff --git a/tempest/api/object_storage/test_object_services.py b/tempest/api/object_storage/test_object_services.py
index 556ca2f716..d3cdb7229e 100644
--- a/tempest/api/object_storage/test_object_services.py
+++ b/tempest/api/object_storage/test_object_services.py
@@ -967,7 +967,6 @@ class PublicObjectTest(base.BaseObjectTest):
     @classmethod
     def setup_credentials(cls):
         super(PublicObjectTest, cls).setup_credentials()
-        cls.os = cls.os_roles_operator
         cls.os_alt = cls.os_roles_operator_alt
 
     @classmethod