diff --git a/releasenotes/notes/Set-default-of-operator_role-to-member-f9c3abd2ebde23b7.yaml b/releasenotes/notes/Set-default-of-operator_role-to-member-f9c3abd2ebde23b7.yaml
new file mode 100644
index 0000000..980f4ca
--- /dev/null
+++ b/releasenotes/notes/Set-default-of-operator_role-to-member-f9c3abd2ebde23b7.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    ``Member`` role has been deprecated and replaced by ``member``. Therefore
+    the default value of config option ``[object-storage].operator_role`` is
+    changed to ``member``. (Fixes bug #1330132)
diff --git a/tempest/config.py b/tempest/config.py
index 204d977..e4e17f1 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1021,7 +1021,7 @@
                help="Number of seconds to wait while looping to check the "
                     "status of a container to container synchronization"),
     cfg.StrOpt('operator_role',
-               default='Member',
+               default='member',
                help="Role to add to users created for swift tests to "
                     "enable creating containers"),
     cfg.StrOpt('reseller_admin_role',
diff --git a/tempest/lib/common/dynamic_creds.py b/tempest/lib/common/dynamic_creds.py
index f27e926..8b82391 100644
--- a/tempest/lib/common/dynamic_creds.py
+++ b/tempest/lib/common/dynamic_creds.py
@@ -207,10 +207,10 @@
         # our newly created user has a role on the newly created project.
         if self.identity_version == 'v3' and not role_assigned:
             try:
-                self.creds_client.create_user_role('Member')
+                self.creds_client.create_user_role('member')
             except lib_exc.Conflict:
-                LOG.warning('Member role already exists, ignoring conflict.')
-            self.creds_client.assign_user_role(user, project, 'Member')
+                LOG.warning('member role already exists, ignoring conflict.')
+            self.creds_client.assign_user_role(user, project, 'member')
 
         creds = self.creds_client.get_credentials(user, project, user_password)
         return cred_provider.TestResources(creds)
diff --git a/tempest/tests/lib/common/test_dynamic_creds.py b/tempest/tests/lib/common/test_dynamic_creds.py
index d1d82d1..e9073cc 100644
--- a/tempest/tests/lib/common/test_dynamic_creds.py
+++ b/tempest/tests/lib/common/test_dynamic_creds.py
@@ -111,7 +111,7 @@
                           (200,
                            {'roles': [{'id': id, 'name': name},
                                       {'id': '1', 'name': 'FakeRole'},
-                                      {'id': '2', 'name': 'Member'}]}))))
+                                      {'id': '2', 'name': 'member'}]}))))
         return roles_fix
 
     def _mock_list_2_roles(self):
@@ -140,7 +140,7 @@
             return_value=(rest_client.ResponseBody
                           (200, {'roles': [
                               {'id': '1', 'name': 'FakeRole'},
-                              {'id': '2', 'name': 'Member'}]}))))
+                              {'id': '2', 'name': 'member'}]}))))
         return roles_fix
 
     def _mock_list_ec2_credentials(self, user_id, tenant_id):
@@ -665,6 +665,6 @@
         with mock.patch('tempest.lib.common.dynamic_creds.LOG') as log_mock:
             creds._create_creds()
             log_mock.warning.assert_called_once_with(
-                "Member role already exists, ignoring conflict.")
+                "member role already exists, ignoring conflict.")
         creds.creds_client.assign_user_role.assert_called_once_with(
-            mock.ANY, mock.ANY, 'Member')
+            mock.ANY, mock.ANY, 'member')