diff --git a/qubes/app.py b/qubes/app.py
index 19021663..bdc2c904 100644
--- a/qubes/app.py
+++ b/qubes/app.py
@@ -1250,11 +1250,14 @@ class Qubes(qubes.PropertyHolder):
             oldvalue=None):
         # pylint: disable=unused-argument,invalid-name
         for vm in self.domains:
-            if not vm.provides_network and vm.property_is_default('netvm'):
+            if hasattr(vm, 'provides_network') and vm.provides_network and \
+                    hasattr(vm, 'netvm') and vm.property_is_default('netvm'):
                 # fire property-del:netvm as it is responsible for resetting
                 # netvm to it's default value
+                vm.fire_event('property-pre-del:netvm', pre_event=True,
+                    name='netvm', oldvalue=oldvalue)
                 vm.fire_event('property-del:netvm',
-                    name='netvm', newvalue=newvalue, oldvalue=oldvalue)
+                    name='netvm', oldvalue=oldvalue)
 
 
     @qubes.events.handler('property-set:default_netvm')
@@ -1262,8 +1265,11 @@ class Qubes(qubes.PropertyHolder):
             oldvalue=None):
         # pylint: disable=unused-argument
         for vm in self.domains:
-            if hasattr(vm, 'netvm') and vm.property_is_default('netvm'):
+            if hasattr(vm, 'provides_network') and not vm.provides_network and \
+                    hasattr(vm, 'netvm') and vm.property_is_default('netvm'):
                 # fire property-del:netvm as it is responsible for resetting
                 # netvm to it's default value
+                vm.fire_event('property-pre-del:netvm', pre_event=True,
+                    name='netvm', oldvalue=oldvalue)
                 vm.fire_event('property-del:netvm',
                     name='netvm', oldvalue=oldvalue)