diff --git a/netbox/dcim/forms/common.py b/netbox/dcim/forms/common.py
index d069b460a..ad4064f66 100644
--- a/netbox/dcim/forms/common.py
+++ b/netbox/dcim/forms/common.py
@@ -43,7 +43,6 @@ class InterfaceCommonForm(forms.Form):
         super().clean()
 
         parent_field = 'device' if 'device' in self.cleaned_data else 'virtual_machine'
-        interface_mode = get_field_value(self, parent_field)
         if 'tagged_vlans' in self.fields.keys():
             tagged_vlans = self.cleaned_data.get('tagged_vlans') if self.is_bound else \
                 self.get_initial_for_field(self.fields['tagged_vlans'], 'tagged_vlans')
diff --git a/netbox/dcim/tests/test_api.py b/netbox/dcim/tests/test_api.py
index 2e70fbc4b..4e09f3aba 100644
--- a/netbox/dcim/tests/test_api.py
+++ b/netbox/dcim/tests/test_api.py
@@ -14,7 +14,7 @@ from ipam.models import ASN, RIR, VLAN, VRF
 from netbox.api.serializers import GenericObjectSerializer
 from tenancy.models import Tenant
 from users.models import User
-from utilities.testing import APITestCase, APIViewTestCases, create_test_device, disable_warnings
+from utilities.testing import APITestCase, APIViewTestCases, create_test_device
 from virtualization.models import Cluster, ClusterType
 from wireless.choices import WirelessChannelChoices
 from wireless.models import WirelessLAN
@@ -1782,8 +1782,6 @@ class InterfaceTest(Mixins.ComponentTraceMixin, APIViewTestCases.APIViewTestCase
         POST a single object without permission.
         """
         self.add_permissions('dcim.add_interface')
-        url = self._get_list_url()
-        initial_count = self._get_queryset().count()
 
         device = Device.objects.first()
         vlans = VLAN.objects.all()[0:3]