diff --git a/xos/synchronizer/event_steps/auth_event.py b/xos/synchronizer/event_steps/auth_event.py
index 6786c98..e534aee 100644
--- a/xos/synchronizer/event_steps/auth_event.py
+++ b/xos/synchronizer/event_steps/auth_event.py
@@ -38,4 +38,4 @@
             raise Exception("authentication.events: Cannot find att-workflow-driver service instance for this event")
 
         si.authentication_state = value["authenticationState"];
-        si.save(update_fields=["authentication_state", "updated"], always_update_timestamp=True)
+        si.save_changed_fields(always_update_timestamp=True)
diff --git a/xos/synchronizer/event_steps/dhcp_event.py b/xos/synchronizer/event_steps/dhcp_event.py
index 3d04e96..ddd1e31 100644
--- a/xos/synchronizer/event_steps/dhcp_event.py
+++ b/xos/synchronizer/event_steps/dhcp_event.py
@@ -43,7 +43,7 @@
         si.dhcp_state = value["messageType"];
         si.ip_address = value["ipAddress"];
         si.mac_address = value["macAddress"];
-        si.save(update_fields=["dhcp_state", "ip_address", "mac_address", "updated"], always_update_timestamp=True)
+        si.save_changed_fields(always_update_timestamp=True)
         # subscriber = RCORDSubscriber.objects.get(onu_device=onu_sn)
         #
         #
diff --git a/xos/synchronizer/event_steps/onu_event.py b/xos/synchronizer/event_steps/onu_event.py
index 4b770a1..d205a59 100644
--- a/xos/synchronizer/event_steps/onu_event.py
+++ b/xos/synchronizer/event_steps/onu_event.py
@@ -59,6 +59,6 @@
             att_si.authentication_state = "AWAITING"
         else:
             self.log.warn("onu.events: Unkown status value: %s" % value["status"], value=value)
-        att_si.save(always_update_timestamp=True)
+        att_si.save_changed_fields(always_update_timestamp=True)
 
 
diff --git a/xos/synchronizer/event_steps/test_auth_event.py b/xos/synchronizer/event_steps/test_auth_event.py
index e04f70b..5587940 100644
--- a/xos/synchronizer/event_steps/test_auth_event.py
+++ b/xos/synchronizer/event_steps/test_auth_event.py
@@ -107,5 +107,5 @@
 
             self.event_step.process_event(self.event)
 
-            self.hippie_si.save.assert_called_with(always_update_timestamp=True, update_fields=['authentication_state', 'updated'])
+            self.hippie_si.save.assert_called_with(always_update_timestamp=True, update_fields=['authentication_state', 'serial_number', 'updated'])
             self.assertEqual(self.hippie_si.authentication_state, 'APPROVED')