diff --git a/src/config/svc-monitor/svc_monitor/snat_agent.py b/src/config/svc-monitor/svc_monitor/snat_agent.py
index 35518929a48..18d1ae437a1 100644
--- a/src/config/svc-monitor/svc_monitor/snat_agent.py
+++ b/src/config/svc-monitor/svc_monitor/snat_agent.py
@@ -216,8 +216,10 @@ def delete_snat_instance(self, router_obj):
             self._vnc_lib.route_table_delete(id=rt_obj.uuid)
 
         # Delete service instance
-        if si_obj:
-            self._vnc_lib.service_instance_delete(id=si_uuid)
+        if not si_obj:
+            return
+
+        self._vnc_lib.service_instance_delete(id=si_uuid)
 
         # Delete left network
         vn_name = '%s_%s' % (svc_info.get_snat_left_vn_prefix(),
diff --git a/src/config/svc-monitor/svc_monitor/svc_monitor.py b/src/config/svc-monitor/svc_monitor/svc_monitor.py
index dd2107e5d0c..c34d5d03c94 100644
--- a/src/config/svc-monitor/svc_monitor/svc_monitor.py
+++ b/src/config/svc-monitor/svc_monitor/svc_monitor.py
@@ -546,7 +546,7 @@ def timer_callback(monitor):
             continue
         iip_delete_list.append(iip)
     for iip in iip_delete_list:
-        monitor.port_tuple_agent.delete_shared_iip(iip.uuid)
+        monitor.port_tuple_agent.delete_shared_iip(iip)
 
     # delete vms without si
     vm_delete_list = []