diff --git a/kvmagent/kvmagent/plugins/vm_plugin.py b/kvmagent/kvmagent/plugins/vm_plugin.py
index f07fbae501..5256243d3f 100644
--- a/kvmagent/kvmagent/plugins/vm_plugin.py
+++ b/kvmagent/kvmagent/plugins/vm_plugin.py
@@ -342,7 +342,7 @@ def delete_stale_chains(self):
         for vm in vms:
             if is_namespace_used():
                 vm_id_node = find_zstack_metadata_node(etree.fromstring(vm.domain_xml), 'internalId')
-                if not vm_id_node:
+                if vm_id_node is None:
                     continue
 
                 vm_id = vm_id_node.text