diff --git a/unit_tests/test_lib_charm_openstack_designate.py b/unit_tests/test_lib_charm_openstack_designate.py
index 00b782d..4d694d8 100644
--- a/unit_tests/test_lib_charm_openstack_designate.py
+++ b/unit_tests/test_lib_charm_openstack_designate.py
@@ -304,8 +304,8 @@ class TestDesignateAdapters(Helper):
             isinstance(
                 b.other,
                 designate.openstack_adapters.OpenStackRelationAdapter))
-        self.assertTrue(isinstance(b.options,
-                                   designate.DesignateConfigurationAdapter))
+        self.assertIsInstance(b.options,
+                              designate.DesignateConfigurationAdapter)
 
 
 class TestDesignateCharm(Helper):