diff --git a/senlinclient/tests/unit/test_format_utils.py b/senlinclient/tests/unit/test_format_utils.py
index b4f47056..e14e203a 100644
--- a/senlinclient/tests/unit/test_format_utils.py
+++ b/senlinclient/tests/unit/test_format_utils.py
@@ -10,9 +10,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import json
 import yaml
 
+from oslo_serialization import jsonutils
+
 from osc_lib.tests import utils
 from senlinclient.common import format_utils
 
@@ -46,7 +47,7 @@ class TestFormats(utils.TestCommand):
     def test_json_format(self):
         self.cmd = ShowJson(self.app, None)
         parsed_args = self.check_parser(self.cmd, [], [])
-        expected = json.dumps(dict(zip(columns, data)), indent=2)
+        expected = jsonutils.dumps(dict(zip(columns, data)), indent=2)
 
         self.cmd.run(parsed_args)
 
diff --git a/senlinclient/tests/unit/v1/fakes.py b/senlinclient/tests/unit/v1/fakes.py
index 8acadedd..508f5228 100644
--- a/senlinclient/tests/unit/v1/fakes.py
+++ b/senlinclient/tests/unit/v1/fakes.py
@@ -12,12 +12,11 @@
 
 import sys
 
-import json
 import mock
 from osc_lib.tests import utils
 import requests
-import six
 
+from oslo_serialization import jsonutils
 
 AUTH_TOKEN = "foobar"
 AUTH_URL = "http://0.0.0.0"
@@ -158,9 +157,7 @@ class FakeResponse(requests.Response):
         self.status_code = status_code
 
         self.headers.update(headers)
-        self._content = json.dumps(data)
-        if not isinstance(self._content, six.binary_type):
-            self._content = self._content.encode()
+        self._content = jsonutils.dump_as_bytes(data)
 
 
 class FakeClusteringv1Client(object):