diff --git a/lower-constraints.txt b/lower-constraints.txt
index a3202e88..c826905a 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -59,7 +59,7 @@ oslo.context==2.20.0
 oslo.i18n==3.20.0
 oslo.log==3.37.0
 oslo.policy==1.34.0
-oslo.serialization==2.25.0
+oslo.serialization==2.18.0
 oslo.utils==3.36.0
 osprofiler==2.3.0
 packaging==17.1
@@ -80,7 +80,7 @@ python-cinderclient==3.5.0
 python-dateutil==2.7.0
 python-glanceclient==2.9.1
 python-keystoneclient==3.15.0
-python-magnumclient==2.6.0
+python-magnumclient==2.11.0
 python-mimeparse==1.6.0
 python-neutronclient==6.7.0
 python-novaclient==10.1.0
diff --git a/magnum_ui/test/api_tests/test_rest_api.py b/magnum_ui/test/api_tests/test_rest_api.py
index 13191787..e4c9a7a4 100644
--- a/magnum_ui/test/api_tests/test_rest_api.py
+++ b/magnum_ui/test/api_tests/test_rest_api.py
@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
 import mock
 
+from oslo_serialization import jsonutils
+
 from magnum_ui.api.rest import magnum
 from magnum_ui.test import test_data
 from openstack_dashboard.test import helpers as test
@@ -42,7 +43,7 @@ class MagnumRestTestCase(test.TestCase):
     def test_cluster_template_create(self, client):
         test_cluster_templates = mock_resource(TEST.cluster_templates.list())
         test_cluster_template = test_cluster_templates[0]
-        test_body = json.dumps(test_cluster_template.to_dict())
+        test_body = jsonutils.dumps(test_cluster_template.to_dict())
         request = self.mock_rest_request(body=test_body)
         client.cluster_template_create.return_value = test_cluster_template
         response = magnum.ClusterTemplates().post(request)
@@ -83,7 +84,7 @@ class MagnumRestTestCase(test.TestCase):
     def test_cluster_create(self, client):
         test_clusters = mock_resource(TEST.clusters.list())
         test_cluster = test_clusters[0]
-        test_body = json.dumps(test_cluster.to_dict())
+        test_body = jsonutils.dumps(test_cluster.to_dict())
         request = self.mock_rest_request(body=test_body)
         client.cluster_create.return_value = test_cluster
         response = magnum.Clusters().post(request)
@@ -111,7 +112,7 @@ class MagnumRestTestCase(test.TestCase):
     def test_certificate_create(self, client):
         test_certificates = mock_resource(TEST.certificates.list())
         test_certificate = test_certificates[0]
-        test_body = json.dumps(test_certificate.to_dict())
+        test_body = jsonutils.dumps(test_certificate.to_dict())
         request = self.mock_rest_request(body=test_body)
 
         test_res_list = mock_resource(TEST.certificate_res_list.list())
@@ -119,7 +120,7 @@ class MagnumRestTestCase(test.TestCase):
         client.certificate_create.return_value = test_res
 
         response = magnum.Certificates().post(request)
-        res_body = json.loads(response.content.decode('utf-8'))
+        res_body = jsonutils.loads(response.content.decode('utf-8'))
 
         self.assertStatusCode(response, 201)
         self.assertEqual(res_body['pem'], test_res.to_dict()['pem'])
diff --git a/requirements.txt b/requirements.txt
index f58bc7cb..87377a96 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,6 +8,6 @@
 #
 # PBR should always appear first
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
-python-magnumclient>=2.6.0 # Apache-2.0
+python-magnumclient>=2.11.0 # Apache-2.0
 
 horizon>=15.0.0.0b1 # Apache-2.0