diff --git a/netbox/circuits/tests/test_api.py b/netbox/circuits/tests/test_api.py
index 0e588fe16..0a9ef0ab6 100644
--- a/netbox/circuits/tests/test_api.py
+++ b/netbox/circuits/tests/test_api.py
@@ -69,7 +69,7 @@ class ProviderTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:provider-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Provider.objects.count(), 4)
@@ -85,7 +85,7 @@ class ProviderTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:provider-detail', kwargs={'pk': self.provider1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Provider.objects.count(), 3)
@@ -136,7 +136,7 @@ class CircuitTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuittype-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(CircuitType.objects.count(), 4)
@@ -152,7 +152,7 @@ class CircuitTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuittype-detail', kwargs={'pk': self.circuittype1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(CircuitType.objects.count(), 3)
@@ -208,7 +208,7 @@ class CircuitTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuit-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Circuit.objects.count(), 4)
@@ -226,7 +226,7 @@ class CircuitTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuit-detail', kwargs={'pk': self.circuit1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Circuit.objects.count(), 3)
@@ -293,7 +293,7 @@ class CircuitTerminationTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuittermination-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(CircuitTermination.objects.count(), 4)
@@ -313,7 +313,7 @@ class CircuitTerminationTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('circuits-api:circuittermination-detail', kwargs={'pk': self.circuittermination1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(CircuitTermination.objects.count(), 3)
diff --git a/netbox/dcim/tests/test_api.py b/netbox/dcim/tests/test_api.py
index bec333974..68367e3ac 100644
--- a/netbox/dcim/tests/test_api.py
+++ b/netbox/dcim/tests/test_api.py
@@ -51,7 +51,7 @@ class RegionTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:region-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Region.objects.count(), 4)
@@ -67,7 +67,7 @@ class RegionTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:region-detail', kwargs={'pk': self.region1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Region.objects.count(), 3)
@@ -142,7 +142,7 @@ class SiteTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:site-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Site.objects.count(), 4)
@@ -160,7 +160,7 @@ class SiteTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:site-detail', kwargs={'pk': self.site1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Site.objects.count(), 3)
@@ -215,7 +215,7 @@ class RackGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackgroup-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(RackGroup.objects.count(), 4)
@@ -233,7 +233,7 @@ class RackGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackgroup-detail', kwargs={'pk': self.rackgroup1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(RackGroup.objects.count(), 3)
@@ -286,7 +286,7 @@ class RackRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackrole-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(RackRole.objects.count(), 4)
@@ -304,7 +304,7 @@ class RackRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackrole-detail', kwargs={'pk': self.rackrole1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(RackRole.objects.count(), 3)
@@ -377,7 +377,7 @@ class RackTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rack-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Rack.objects.count(), 4)
@@ -397,7 +397,7 @@ class RackTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rack-detail', kwargs={'pk': self.rack1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Rack.objects.count(), 3)
@@ -461,7 +461,7 @@ class RackReservationTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackreservation-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(RackReservation.objects.count(), 4)
@@ -481,7 +481,7 @@ class RackReservationTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:rackreservation-detail', kwargs={'pk': self.rackreservation1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(RackReservation.objects.count(), 3)
@@ -532,7 +532,7 @@ class ManufacturerTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:manufacturer-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Manufacturer.objects.count(), 4)
@@ -548,7 +548,7 @@ class ManufacturerTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:manufacturer-detail', kwargs={'pk': self.manufacturer1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Manufacturer.objects.count(), 3)
@@ -608,7 +608,7 @@ class DeviceTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicetype-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(DeviceType.objects.count(), 4)
@@ -626,7 +626,7 @@ class DeviceTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicetype-detail', kwargs={'pk': self.devicetype1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(DeviceType.objects.count(), 3)
@@ -688,7 +688,7 @@ class ConsolePortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleporttemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ConsolePortTemplate.objects.count(), 4)
@@ -704,7 +704,7 @@ class ConsolePortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleporttemplate-detail', kwargs={'pk': self.consoleporttemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ConsolePortTemplate.objects.count(), 3)
@@ -764,7 +764,7 @@ class ConsoleServerPortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleserverporttemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ConsoleServerPortTemplate.objects.count(), 4)
@@ -780,7 +780,7 @@ class ConsoleServerPortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleserverporttemplate-detail', kwargs={'pk': self.consoleserverporttemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ConsoleServerPortTemplate.objects.count(), 3)
@@ -840,7 +840,7 @@ class PowerPortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:powerporttemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(PowerPortTemplate.objects.count(), 4)
@@ -856,7 +856,7 @@ class PowerPortTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:powerporttemplate-detail', kwargs={'pk': self.powerporttemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(PowerPortTemplate.objects.count(), 3)
@@ -916,7 +916,7 @@ class PowerOutletTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:poweroutlettemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(PowerOutletTemplate.objects.count(), 4)
@@ -932,7 +932,7 @@ class PowerOutletTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:poweroutlettemplate-detail', kwargs={'pk': self.poweroutlettemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(PowerOutletTemplate.objects.count(), 3)
@@ -992,7 +992,7 @@ class InterfaceTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interfacetemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(InterfaceTemplate.objects.count(), 4)
@@ -1008,7 +1008,7 @@ class InterfaceTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interfacetemplate-detail', kwargs={'pk': self.interfacetemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(InterfaceTemplate.objects.count(), 3)
@@ -1068,7 +1068,7 @@ class DeviceBayTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicebaytemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(DeviceBayTemplate.objects.count(), 4)
@@ -1084,7 +1084,7 @@ class DeviceBayTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicebaytemplate-detail', kwargs={'pk': self.devicebaytemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(DeviceBayTemplate.objects.count(), 3)
@@ -1141,7 +1141,7 @@ class DeviceRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicerole-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(DeviceRole.objects.count(), 4)
@@ -1159,7 +1159,7 @@ class DeviceRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicerole-detail', kwargs={'pk': self.devicerole1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(DeviceRole.objects.count(), 3)
@@ -1211,7 +1211,7 @@ class PlatformTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:platform-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Platform.objects.count(), 4)
@@ -1227,7 +1227,7 @@ class PlatformTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:platform-detail', kwargs={'pk': self.platform1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Platform.objects.count(), 3)
@@ -1301,7 +1301,7 @@ class DeviceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:device-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Device.objects.count(), 4)
@@ -1321,7 +1321,7 @@ class DeviceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:device-detail', kwargs={'pk': self.device1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Device.objects.count(), 3)
@@ -1385,7 +1385,7 @@ class ConsolePortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleport-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ConsolePort.objects.count(), 4)
@@ -1404,7 +1404,7 @@ class ConsolePortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleport-detail', kwargs={'pk': self.consoleport1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ConsolePort.objects.count(), 3)
@@ -1466,7 +1466,7 @@ class ConsoleServerPortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleserverport-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ConsoleServerPort.objects.count(), 4)
@@ -1482,7 +1482,7 @@ class ConsoleServerPortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:consoleserverport-detail', kwargs={'pk': self.consoleserverport1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ConsoleServerPort.objects.count(), 3)
@@ -1543,7 +1543,7 @@ class PowerPortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:powerport-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(PowerPort.objects.count(), 4)
@@ -1562,7 +1562,7 @@ class PowerPortTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:powerport-detail', kwargs={'pk': self.powerport1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(PowerPort.objects.count(), 3)
@@ -1624,7 +1624,7 @@ class PowerOutletTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:poweroutlet-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(PowerOutlet.objects.count(), 4)
@@ -1640,7 +1640,7 @@ class PowerOutletTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:poweroutlet-detail', kwargs={'pk': self.poweroutlet1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(PowerOutlet.objects.count(), 3)
@@ -1722,7 +1722,7 @@ class InterfaceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interface-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Interface.objects.count(), 4)
@@ -1743,7 +1743,7 @@ class InterfaceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interface-detail', kwargs={'pk': self.interface1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Interface.objects.count(), 4)
@@ -1814,7 +1814,7 @@ class DeviceBayTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicebay-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(DeviceBay.objects.count(), 4)
@@ -1832,7 +1832,7 @@ class DeviceBayTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:devicebay-detail', kwargs={'pk': self.devicebay1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(DeviceBay.objects.count(), 3)
@@ -1896,7 +1896,7 @@ class InventoryItemTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:inventoryitem-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(InventoryItem.objects.count(), 4)
@@ -1916,7 +1916,7 @@ class InventoryItemTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:inventoryitem-detail', kwargs={'pk': self.inventoryitem1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(InventoryItem.objects.count(), 3)
@@ -2081,7 +2081,7 @@ class InterfaceConnectionTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interfaceconnection-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(InterfaceConnection.objects.count(), 4)
@@ -2100,7 +2100,7 @@ class InterfaceConnectionTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('dcim-api:interfaceconnection-detail', kwargs={'pk': self.interfaceconnection1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(InterfaceConnection.objects.count(), 3)
diff --git a/netbox/extras/tests/test_api.py b/netbox/extras/tests/test_api.py
index fde9c3185..46e0b3bda 100644
--- a/netbox/extras/tests/test_api.py
+++ b/netbox/extras/tests/test_api.py
@@ -54,7 +54,7 @@ class GraphTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('extras-api:graph-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Graph.objects.count(), 4)
@@ -72,7 +72,7 @@ class GraphTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('extras-api:graph-detail', kwargs={'pk': self.graph1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Graph.objects.count(), 3)
@@ -135,7 +135,7 @@ class ExportTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('extras-api:exporttemplate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ExportTemplate.objects.count(), 4)
@@ -153,7 +153,7 @@ class ExportTemplateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('extras-api:exporttemplate-detail', kwargs={'pk': self.exporttemplate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ExportTemplate.objects.count(), 3)
diff --git a/netbox/ipam/tests/test_api.py b/netbox/ipam/tests/test_api.py
index b39116b9f..55a69c7c3 100644
--- a/netbox/ipam/tests/test_api.py
+++ b/netbox/ipam/tests/test_api.py
@@ -47,7 +47,7 @@ class VRFTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vrf-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(VRF.objects.count(), 4)
@@ -63,7 +63,7 @@ class VRFTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vrf-detail', kwargs={'pk': self.vrf1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(VRF.objects.count(), 3)
@@ -114,7 +114,7 @@ class RIRTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:rir-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(RIR.objects.count(), 4)
@@ -130,7 +130,7 @@ class RIRTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:rir-detail', kwargs={'pk': self.rir1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(RIR.objects.count(), 3)
@@ -183,7 +183,7 @@ class AggregateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:aggregate-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Aggregate.objects.count(), 4)
@@ -199,7 +199,7 @@ class AggregateTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:aggregate-detail', kwargs={'pk': self.aggregate1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Aggregate.objects.count(), 3)
@@ -250,7 +250,7 @@ class RoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:role-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Role.objects.count(), 4)
@@ -266,7 +266,7 @@ class RoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:role-detail', kwargs={'pk': self.role1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Role.objects.count(), 3)
@@ -324,7 +324,7 @@ class PrefixTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:prefix-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Prefix.objects.count(), 4)
@@ -346,7 +346,7 @@ class PrefixTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:prefix-detail', kwargs={'pk': self.prefix1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Prefix.objects.count(), 3)
@@ -390,7 +390,7 @@ class PrefixTest(HttpStatusMixin, APITestCase):
             data = {
                 'description': 'Test IP {}'.format(i)
             }
-            response = self.client.post(url, data, **self.header)
+            response = self.client.post(url, data, format='json', **self.header)
             if response.status_code != status.HTTP_201_CREATED:
                 assert False, response.content
             self.assertHttpStatus(response, status.HTTP_201_CREATED)
@@ -458,7 +458,7 @@ class IPAddressTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:ipaddress-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(IPAddress.objects.count(), 4)
@@ -474,7 +474,7 @@ class IPAddressTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:ipaddress-detail', kwargs={'pk': self.ipaddress1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(IPAddress.objects.count(), 3)
@@ -525,7 +525,7 @@ class VLANGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vlangroup-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(VLANGroup.objects.count(), 4)
@@ -541,7 +541,7 @@ class VLANGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vlangroup-detail', kwargs={'pk': self.vlangroup1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(VLANGroup.objects.count(), 3)
@@ -592,7 +592,7 @@ class VLANTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vlan-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(VLAN.objects.count(), 4)
@@ -608,7 +608,7 @@ class VLANTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:vlan-detail', kwargs={'pk': self.vlan1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(VLAN.objects.count(), 3)
@@ -677,7 +677,7 @@ class ServiceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:service-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Service.objects.count(), 4)
@@ -697,7 +697,7 @@ class ServiceTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('ipam-api:service-detail', kwargs={'pk': self.service1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Service.objects.count(), 3)
diff --git a/netbox/secrets/tests/test_api.py b/netbox/secrets/tests/test_api.py
index 02b4d3e90..3a51959c1 100644
--- a/netbox/secrets/tests/test_api.py
+++ b/netbox/secrets/tests/test_api.py
@@ -86,7 +86,7 @@ class SecretRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('secrets-api:secretrole-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(SecretRole.objects.count(), 4)
@@ -102,7 +102,7 @@ class SecretRoleTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('secrets-api:secretrole-detail', kwargs={'pk': self.secretrole1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(SecretRole.objects.count(), 3)
@@ -191,7 +191,7 @@ class SecretTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('secrets-api:secret-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(response.data['plaintext'], data['plaintext'])
@@ -210,7 +210,7 @@ class SecretTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('secrets-api:secret-detail', kwargs={'pk': self.secret1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(response.data['plaintext'], data['plaintext'])
diff --git a/netbox/tenancy/tests/test_api.py b/netbox/tenancy/tests/test_api.py
index 1ac05ea89..2930d464a 100644
--- a/netbox/tenancy/tests/test_api.py
+++ b/netbox/tenancy/tests/test_api.py
@@ -44,7 +44,7 @@ class TenantGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('tenancy-api:tenantgroup-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(TenantGroup.objects.count(), 4)
@@ -60,7 +60,7 @@ class TenantGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('tenancy-api:tenantgroup-detail', kwargs={'pk': self.tenantgroup1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(TenantGroup.objects.count(), 3)
@@ -114,7 +114,7 @@ class TenantTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('tenancy-api:tenant-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Tenant.objects.count(), 4)
@@ -132,7 +132,7 @@ class TenantTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('tenancy-api:tenant-detail', kwargs={'pk': self.tenant1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Tenant.objects.count(), 3)
diff --git a/netbox/virtualization/tests/test_api.py b/netbox/virtualization/tests/test_api.py
index f83e0ea58..ee06ba31b 100644
--- a/netbox/virtualization/tests/test_api.py
+++ b/netbox/virtualization/tests/test_api.py
@@ -44,7 +44,7 @@ class ClusterTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:clustertype-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ClusterType.objects.count(), 4)
@@ -60,7 +60,7 @@ class ClusterTypeTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:clustertype-detail', kwargs={'pk': self.clustertype1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ClusterType.objects.count(), 3)
@@ -111,7 +111,7 @@ class ClusterGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:clustergroup-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(ClusterGroup.objects.count(), 4)
@@ -127,7 +127,7 @@ class ClusterGroupTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:clustergroup-detail', kwargs={'pk': self.clustergroup1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(ClusterGroup.objects.count(), 3)
@@ -182,7 +182,7 @@ class ClusterTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:cluster-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(Cluster.objects.count(), 4)
@@ -202,7 +202,7 @@ class ClusterTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:cluster-detail', kwargs={'pk': self.cluster1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(Cluster.objects.count(), 3)
@@ -258,7 +258,7 @@ class VirtualMachineTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:virtualmachine-list')
-        response = self.client.post(url, data, **self.header)
+        response = self.client.post(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_201_CREATED)
         self.assertEqual(VirtualMachine.objects.count(), 4)
@@ -279,7 +279,7 @@ class VirtualMachineTest(HttpStatusMixin, APITestCase):
         }
 
         url = reverse('virtualization-api:virtualmachine-detail', kwargs={'pk': self.virtualmachine1.pk})
-        response = self.client.put(url, data, **self.header)
+        response = self.client.put(url, data, format='json', **self.header)
 
         self.assertHttpStatus(response, status.HTTP_200_OK)
         self.assertEqual(VirtualMachine.objects.count(), 3)