diff --git a/netbox/ipam/forms/model_forms.py b/netbox/ipam/forms/model_forms.py
index 95af67915..f5e3bca30 100644
--- a/netbox/ipam/forms/model_forms.py
+++ b/netbox/ipam/forms/model_forms.py
@@ -612,6 +612,9 @@ class VLANGroupForm(NetBoxModelForm):
             except ObjectDoesNotExist:
                 pass
 
+            if self.instance and scope_type_id != self.instance.scope_type_id:
+                self.initial['scope'] = None
+
     def clean(self):
         super().clean()