diff --git a/qubes/app.py b/qubes/app.py
index eb28165c..f56cb2a8 100644
--- a/qubes/app.py
+++ b/qubes/app.py
@@ -487,9 +487,9 @@ class VMCollection(object):
             for vm in cur_vm.connected_vms:
                 if vm in dependent_vms:
                     continue
-                dependent_vms.add(vm.qid)
+                dependent_vms.add(vm)
 #               if vm.is_netvm():
-                new_vms.add(vm.qid)
+                new_vms.add(vm)
 
         return dependent_vms
 
diff --git a/qubes/vm/mix/net.py b/qubes/vm/mix/net.py
index b8f851d1..e7227faf 100644
--- a/qubes/vm/mix/net.py
+++ b/qubes/vm/mix/net.py
@@ -284,7 +284,7 @@ class NetVMMixin(qubes.events.Emitter):
         '''
 
         dev_basepath = '/local/domain/%d/device/vif' % self.xid
-        for dev in self.app.vmm.xs.ls('', dev_basepath):
+        for dev in self.app.vmm.xs.ls('', dev_basepath) or []:
             # check if backend domain is alive
             backend_xid = int(self.app.vmm.xs.read('',
                 '{}/{}/backend-id'.format(dev_basepath, dev)))