diff --git a/openstackclient/tests/volume/v1/test_qos_specs.py b/openstackclient/tests/volume/v1/test_qos_specs.py
index 1a6c0fa4ed..4943f5df69 100644
--- a/openstackclient/tests/volume/v1/test_qos_specs.py
+++ b/openstackclient/tests/volume/v1/test_qos_specs.py
@@ -62,11 +62,13 @@ class TestQosAssociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.associate.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.type_id
         )
+        self.assertIsNone(result)
 
 
 class TestQosCreate(TestQos):
@@ -204,11 +206,12 @@ class TestQosDelete(TestQos):
         verifylist = [
             ('qos_specs', [volume_fakes.qos_id])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.delete.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
     def test_qos_delete_with_name(self):
         arglist = [
@@ -217,11 +220,12 @@ class TestQosDelete(TestQos):
         verifylist = [
             ('qos_specs', [volume_fakes.qos_name])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.delete.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
 
 class TestQosDisassociate(TestQos):
@@ -253,11 +257,13 @@ class TestQosDisassociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.disassociate.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.type_id
         )
+        self.assertIsNone(result)
 
     def test_qos_disassociate_with_all_volume_types(self):
         self.qos_mock.get.return_value = fakes.FakeResource(
@@ -275,8 +281,10 @@ class TestQosDisassociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.disassociate_all.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
 
 class TestQosList(TestQos):
@@ -351,11 +359,13 @@ class TestQosSet(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.set_keys.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.qos_specs
         )
+        self.assertIsNone(result)
 
 
 class TestQosShow(TestQos):
@@ -436,8 +446,10 @@ class TestQosUnset(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.unset_keys.assert_called_with(
             volume_fakes.qos_id,
             ['iops', 'foo']
         )
+        self.assertIsNone(result)
diff --git a/openstackclient/tests/volume/v1/test_volume.py b/openstackclient/tests/volume/v1/test_volume.py
index 00c509b5d9..35fc917f11 100644
--- a/openstackclient/tests/volume/v1/test_volume.py
+++ b/openstackclient/tests/volume/v1/test_volume.py
@@ -578,6 +578,7 @@ class TestVolumeSet(TestVolume):
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
         result = self.cmd.run(parsed_args)
+
         self.assertEqual(0, result)
         self.assertEqual("No changes requested\n",
                          self.app.log.messages.get('error'))
@@ -596,7 +597,7 @@ class TestVolumeSet(TestVolume):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         kwargs = {
@@ -606,6 +607,7 @@ class TestVolumeSet(TestVolume):
             volume_fakes.volume_id,
             **kwargs
         )
+        self.assertIsNone(result)
 
     def test_volume_set_description(self):
         arglist = [
@@ -621,7 +623,7 @@ class TestVolumeSet(TestVolume):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         kwargs = {
@@ -631,6 +633,7 @@ class TestVolumeSet(TestVolume):
             volume_fakes.volume_id,
             **kwargs
         )
+        self.assertIsNone(result)
 
     def test_volume_set_size(self):
         arglist = [
@@ -646,15 +649,15 @@ class TestVolumeSet(TestVolume):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         size = 130
-
         self.volumes_mock.extend.assert_called_with(
             volume_fakes.volume_id,
             size
         )
+        self.assertIsNone(result)
 
     def test_volume_set_size_smaller(self):
         arglist = [
@@ -671,6 +674,7 @@ class TestVolumeSet(TestVolume):
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
         result = self.cmd.run(parsed_args)
+
         self.assertEqual(0, result)
         self.assertEqual("New size must be greater than %s GB" %
                          volume_fakes.volume_size,
@@ -692,6 +696,7 @@ class TestVolumeSet(TestVolume):
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
         result = self.cmd.run(parsed_args)
+
         self.assertEqual(0, result)
         self.assertEqual("Volume is in %s state, it must be available before "
                          "size can be extended" % 'error',
@@ -711,7 +716,7 @@ class TestVolumeSet(TestVolume):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         metadata = {
@@ -721,3 +726,4 @@ class TestVolumeSet(TestVolume):
             volume_fakes.volume_id,
             metadata
         )
+        self.assertIsNone(result)
diff --git a/openstackclient/tests/volume/v2/test_backup.py b/openstackclient/tests/volume/v2/test_backup.py
index 6fe3f6668c..cc8dff5a36 100644
--- a/openstackclient/tests/volume/v2/test_backup.py
+++ b/openstackclient/tests/volume/v2/test_backup.py
@@ -99,11 +99,12 @@ class TestBackupDelete(TestBackup):
         verifylist = [
             ("backups", [volume_fakes.backup_id])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.backups_mock.delete.assert_called_with(volume_fakes.backup_id)
+        self.assertIsNone(result)
 
 
 class TestBackupList(TestBackup):
@@ -213,9 +214,10 @@ class TestBackupRestore(TestBackup):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
         self.restores_mock.restore.assert_called_with(volume_fakes.backup_id,
                                                       volume_fakes.volume_id)
+        self.assertIsNone(result)
 
 
 class TestBackupShow(TestBackup):
diff --git a/openstackclient/tests/volume/v2/test_qos_specs.py b/openstackclient/tests/volume/v2/test_qos_specs.py
index c826925fda..5232285c85 100644
--- a/openstackclient/tests/volume/v2/test_qos_specs.py
+++ b/openstackclient/tests/volume/v2/test_qos_specs.py
@@ -62,11 +62,13 @@ class TestQosAssociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.associate.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.type_id
         )
+        self.assertIsNone(result)
 
 
 class TestQosCreate(TestQos):
@@ -205,11 +207,12 @@ class TestQosDelete(TestQos):
         verifylist = [
             ('qos_specs', [volume_fakes.qos_id])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.delete.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
     def test_qos_delete_with_name(self):
         arglist = [
@@ -218,11 +221,12 @@ class TestQosDelete(TestQos):
         verifylist = [
             ('qos_specs', [volume_fakes.qos_name])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.delete.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
 
 class TestQosDisassociate(TestQos):
@@ -254,11 +258,13 @@ class TestQosDisassociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.disassociate.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.type_id
         )
+        self.assertIsNone(result)
 
     def test_qos_disassociate_with_all_volume_types(self):
         self.qos_mock.get.return_value = fakes.FakeResource(
@@ -276,8 +282,10 @@ class TestQosDisassociate(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.disassociate_all.assert_called_with(volume_fakes.qos_id)
+        self.assertIsNone(result)
 
 
 class TestQosList(TestQos):
@@ -352,11 +360,13 @@ class TestQosSet(TestQos):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.set_keys.assert_called_with(
             volume_fakes.qos_id,
             volume_fakes.qos_specs
         )
+        self.assertIsNone(result)
 
 
 class TestQosShow(TestQos):
@@ -430,15 +440,16 @@ class TestQosUnset(TestQos):
             '--property', 'iops',
             '--property', 'foo'
         ]
-
         verifylist = [
             ('qos_spec', volume_fakes.qos_id),
             ('property', ['iops', 'foo'])
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.qos_mock.unset_keys.assert_called_with(
             volume_fakes.qos_id,
             ['iops', 'foo']
         )
+        self.assertIsNone(result)
diff --git a/openstackclient/tests/volume/v2/test_snapshot.py b/openstackclient/tests/volume/v2/test_snapshot.py
index 349e8dac85..87e2fccfa8 100644
--- a/openstackclient/tests/volume/v2/test_snapshot.py
+++ b/openstackclient/tests/volume/v2/test_snapshot.py
@@ -97,11 +97,12 @@ class TestSnapshotDelete(TestSnapshot):
         verifylist = [
             ("snapshots", [volume_fakes.snapshot_id])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.snapshots_mock.delete.assert_called_with(volume_fakes.snapshot_id)
+        self.assertIsNone(result)
 
 
 class TestSnapshotList(TestSnapshot):
@@ -231,18 +232,19 @@ class TestSnapshotSet(TestSnapshot):
             ("name", "new_snapshot"),
             ("property", new_property)
         ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        result = self.cmd.take_action(parsed_args)
 
         kwargs = {
             "name": "new_snapshot",
         }
-        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
-        self.cmd.take_action(parsed_args)
-
         self.snapshots_mock.update.assert_called_with(
             volume_fakes.snapshot_id, **kwargs)
         self.snapshots_mock.set_metadata.assert_called_with(
             volume_fakes.snapshot_id, new_property
         )
+        self.assertIsNone(result)
 
 
 class TestSnapshotShow(TestSnapshot):
@@ -296,10 +298,11 @@ class TestSnapshotUnset(TestSnapshot):
             ("snapshot", volume_fakes.snapshot_id),
             ("property", ["foo"])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
-        self.cmd.take_action(parsed_args)
+
+        result = self.cmd.take_action(parsed_args)
 
         self.snapshots_mock.delete_metadata.assert_called_with(
             volume_fakes.snapshot_id, ["foo"]
         )
+        self.assertIsNone(result)
diff --git a/openstackclient/tests/volume/v2/test_type.py b/openstackclient/tests/volume/v2/test_type.py
index 1408b9d93c..b014706b69 100644
--- a/openstackclient/tests/volume/v2/test_type.py
+++ b/openstackclient/tests/volume/v2/test_type.py
@@ -137,11 +137,12 @@ class TestTypeDelete(TestType):
         verifylist = [
             ("volume_type", volume_fakes.type_id)
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.types_mock.delete.assert_called_with(volume_fakes.type_id)
+        self.assertIsNone(result)
 
 
 class TestTypeList(TestType):
@@ -227,7 +228,7 @@ class TestTypeSet(TestType):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         kwargs = {
@@ -237,6 +238,7 @@ class TestTypeSet(TestType):
             volume_fakes.type_id,
             **kwargs
         )
+        self.assertIsNone(result)
 
     def test_type_set_description(self):
         new_desc = 'new_desc'
@@ -252,7 +254,7 @@ class TestTypeSet(TestType):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         # Set expected values
         kwargs = {
@@ -262,6 +264,7 @@ class TestTypeSet(TestType):
             volume_fakes.type_id,
             **kwargs
         )
+        self.assertIsNone(result)
 
     def test_type_set_property(self):
         arglist = [
@@ -276,7 +279,8 @@ class TestTypeSet(TestType):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+        self.assertIsNone(result)
 
         result = self.types_mock.get.return_value._keys
         self.assertIn('myprop', result)
@@ -338,8 +342,8 @@ class TestTypeUnset(TestType):
 
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+        self.assertIsNone(result)
 
         result = self.types_mock.get.return_value._keys
-
         self.assertNotIn('property', result)
diff --git a/openstackclient/tests/volume/v2/test_volume.py b/openstackclient/tests/volume/v2/test_volume.py
index cbca09b286..a836f79ec6 100644
--- a/openstackclient/tests/volume/v2/test_volume.py
+++ b/openstackclient/tests/volume/v2/test_volume.py
@@ -396,11 +396,12 @@ class TestVolumeDelete(TestVolume):
         verifylist = [
             ("volumes", [volumes[0].id])
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
+
         self.volumes_mock.delete.assert_called_with(volumes[0].id)
+        self.assertIsNone(result)
 
     def test_volume_delete_multi_volumes(self):
         volumes = self.setup_volumes_mock(count=3)
@@ -409,14 +410,13 @@ class TestVolumeDelete(TestVolume):
         verifylist = [
             ('volumes', arglist),
         ]
-
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        self.cmd.take_action(parsed_args)
+        result = self.cmd.take_action(parsed_args)
 
         calls = [call(v.id) for v in volumes]
-
         self.volumes_mock.delete.assert_has_calls(calls)
+        self.assertIsNone(result)
 
 
 class TestVolumeList(TestVolume):