diff --git a/neutron/tests/tempest/api/admin/test_routers_flavors.py b/neutron/tests/tempest/api/admin/test_routers_flavors.py
index 4988ba8..7323427 100644
--- a/neutron/tests/tempest/api/admin/test_routers_flavors.py
+++ b/neutron/tests/tempest/api/admin/test_routers_flavors.py
@@ -11,6 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron_lib import constants
 from tempest.lib import exceptions as lib_exc
 from tempest import test
 import testtools
@@ -45,7 +46,7 @@
         cls.flavor = cls.create_flavor(
                 name='special_flavor',
                 description='econonomy class',
-                service_type='L3_ROUTER_NAT')
+                service_type=constants.L3)
         cls.admin_client.create_flavor_service_profile(
             cls.flavor['id'], sp['service_profile']['id'])
         cls.flavor_service_profiles.append((cls.flavor['id'],
@@ -63,7 +64,7 @@
         cls.prem_flavor = cls.create_flavor(
                 name='better_special_flavor',
                 description='econonomy comfort',
-                service_type='L3_ROUTER_NAT')
+                service_type=constants.L3)
         cls.admin_client.create_flavor_service_profile(
             cls.prem_flavor['id'], sp['service_profile']['id'])
         cls.flavor_service_profiles.append((cls.prem_flavor['id'],