diff --git a/qubes/tests/vm/mix/net.py b/qubes/tests/vm/mix/net.py
index dc15c933..dfd844d1 100644
--- a/qubes/tests/vm/mix/net.py
+++ b/qubes/tests/vm/mix/net.py
@@ -35,6 +35,7 @@ class TC_00_NetVMMixin(
     def setUp(self):
         super(TC_00_NetVMMixin, self).setUp()
         self.app = qubes.tests.vm.TestApp()
+        self.app.vmm.offline_mode = True
 
     def setup_netvms(self, vm):
         # usage of QubesVM here means that those tests should be after
diff --git a/qubes/tests/vm/qubesvm.py b/qubes/tests/vm/qubesvm.py
index f4cb0db1..a58c2a23 100644
--- a/qubes/tests/vm/qubesvm.py
+++ b/qubes/tests/vm/qubesvm.py
@@ -146,6 +146,7 @@ class QubesVMTestsMixin(object):
     def setUp(self):
         super(QubesVMTestsMixin, self).setUp()
         self.app = qubes.tests.vm.TestApp()
+        self.app.vmm.offline_mode = True
 
     def get_vm(self, **kwargs):
         return qubes.vm.qubesvm.QubesVM(self.app, None,