diff --git a/netbox/ipam/forms/model_forms.py b/netbox/ipam/forms/model_forms.py
index aaa7abba8..0a92cac63 100644
--- a/netbox/ipam/forms/model_forms.py
+++ b/netbox/ipam/forms/model_forms.py
@@ -354,14 +354,17 @@ class IPAddressForm(TenancyForm, NetBoxModelForm):
         # Do not allow assigning a network ID or broadcast address to an interface.
         if interface:
             if address := self.cleaned_data.get('address'):
-                if address.ip == address.network and address.prefixlen not in (31, 32, 127, 128):
-                    self.add_error(
-                        'interface',
-                        f"{address} is a network ID, which may not be assigned to an interface.")
+                if address.ip == address.network:
+                    msg = f"{address} is a network ID, which may not be assigned to an interface."
+                    if address.version == 4:
+                        if address.prefixlen not in (31, 32):
+                            raise ValidationError(msg)
+                    if address.version == 6:
+                        if address.prefixlen not in (127, 128):
+                            raise ValidationError(msg)
                 if address.ip == address.broadcast:
-                    self.add_error(
-                        'interface',
-                        f"{address} is a broadcast address, which may not be assigned to an interface.")
+                    msg = f"{address} is a broadcast address, which may not be assigned to an interface."
+                    raise ValidationError(msg)
 
     def save(self, *args, **kwargs):
         ipaddress = super().save(*args, **kwargs)