diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 724bff4..1f8c889 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -123,10 +123,10 @@
 # Roles to assign to all users created by tempest (list value)
 #tempest_roles =
 
-# Only applicable when identity.auth_version is v3.Domain within which
-# isolated credentials are provisioned.The default "None" means that
-# the domain from theadmin user is used instead. (string value)
-#tenant_isolation_domain_name = <None>
+# Default domain used when getting v3 credentials. This is the name
+# keystone uses for v2 compatibility. (string value)
+# Deprecated group/name - [auth]/tenant_isolation_domain_name
+#default_credentials_domain_name = Default
 
 # If allow_tenant_isolation is set to True and Neutron is enabled
 # Tempest will try to create a useable network, subnet, and router
diff --git a/tempest/common/accounts.py b/tempest/common/accounts.py
index 78e0e72..27b44f6 100644
--- a/tempest/common/accounts.py
+++ b/tempest/common/accounts.py
@@ -216,7 +216,7 @@
             if ('user_domain_name' in init_attributes and 'user_domain_name'
                     not in hash_attributes):
                 # Allow for the case of domain_name populated from config
-                domain_name = CONF.identity.admin_domain_name
+                domain_name = CONF.auth.default_credentials_domain_name
                 hash_attributes['user_domain_name'] = domain_name
             if all([getattr(creds, k) == hash_attributes[k] for
                    k in init_attributes]):
diff --git a/tempest/common/cred_provider.py b/tempest/common/cred_provider.py
index 2b7e0db..783a5fc 100644
--- a/tempest/common/cred_provider.py
+++ b/tempest/common/cred_provider.py
@@ -84,9 +84,9 @@
         domain_fields = set(x for x in auth.KeystoneV3Credentials.ATTRIBUTES
                             if 'domain' in x)
         if not domain_fields.intersection(kwargs.keys()):
-            # TODO(andreaf) It might be better here to use a dedicated config
-            # option such as CONF.auth.tenant_isolation_domain_name
-            params['user_domain_name'] = CONF.identity.admin_domain_name
+            domain_name = CONF.auth.default_credentials_domain_name
+            params['user_domain_name'] = domain_name
+
         auth_url = CONF.identity.uri_v3
     else:
         auth_url = CONF.identity.uri
diff --git a/tempest/common/isolated_creds.py b/tempest/common/isolated_creds.py
index ff4eda9..7888811 100644
--- a/tempest/common/isolated_creds.py
+++ b/tempest/common/isolated_creds.py
@@ -163,8 +163,8 @@
         self.creds_domain_name = None
         if self.identity_version == 'v3':
             self.creds_domain_name = (
-                CONF.auth.tenant_isolation_domain_name or
-                self.default_admin_creds.project_domain_name)
+                self.default_admin_creds.project_domain_name or
+                CONF.auth.default_credentials_domain_name)
         self.creds_client = get_creds_client(
             self.identity_admin_client, self.creds_domain_name)
 
diff --git a/tempest/config.py b/tempest/config.py
index 5ea4d10..46f84ee 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -67,12 +67,13 @@
     cfg.ListOpt('tempest_roles',
                 help="Roles to assign to all users created by tempest",
                 default=[]),
-    cfg.StrOpt('tenant_isolation_domain_name',
-               default=None,
-               help="Only applicable when identity.auth_version is v3."
-                    "Domain within which isolated credentials are provisioned."
-                    "The default \"None\" means that the domain from the"
-                    "admin user is used instead."),
+    cfg.StrOpt('default_credentials_domain_name',
+               default='Default',
+               help="Default domain used when getting v3 credentials. "
+                    "This is the name keystone uses for v2 compatibility.",
+               deprecated_opts=[cfg.DeprecatedOpt(
+                                'tenant_isolation_domain_name',
+                                group='auth')]),
     cfg.BoolOpt('create_isolated_networks',
                 default=True,
                 help="If allow_tenant_isolation is set to True and Neutron is "
@@ -1257,9 +1258,11 @@
         self.baremetal = _CONF.baremetal
         self.input_scenario = _CONF['input-scenario']
         self.negative = _CONF.negative
-        _CONF.set_default('domain_name', self.identity.admin_domain_name,
+        _CONF.set_default('domain_name',
+                          self.auth.default_credentials_domain_name,
                           group='identity')
-        _CONF.set_default('alt_domain_name', self.identity.admin_domain_name,
+        _CONF.set_default('alt_domain_name',
+                          self.auth.default_credentials_domain_name,
                           group='identity')
 
     def __init__(self, parse_conf=True, config_path=None):