diff --git a/qubes/app.py b/qubes/app.py
index 0177148ff..7e1576b71 100644
--- a/qubes/app.py
+++ b/qubes/app.py
@@ -1473,6 +1473,8 @@ def on_property_pre_set_clockvm(self, event, name, newvalue, oldvalue=None):
     @qubes.events.handler('property-set:clockvm')
     def on_property_set_clockvm(self, event, name, newvalue, oldvalue=None):
         # pylint: disable=unused-argument,no-self-use
+        if oldvalue == newvalue:
+            return
         if oldvalue and oldvalue.features.get('service.clocksync', False):
             del oldvalue.features['service.clocksync']