diff --git a/libvirt/tests/cfg/virtual_network/passt/passt_attach_detach.cfg b/libvirt/tests/cfg/virtual_network/passt/passt_attach_detach.cfg
index e6060d7cfc3..e2d58309f5a 100644
--- a/libvirt/tests/cfg/virtual_network/passt/passt_attach_detach.cfg
+++ b/libvirt/tests/cfg/virtual_network/passt/passt_attach_detach.cfg
@@ -2,6 +2,7 @@
     type = passt_attach_detach
     func_supported_since_libvirt_ver = (9, 0, 0)
     host_iface =
+    host_iface_index =
     outside_ip = 'www.redhat.com'
     start_vm = no
     mtu = 65520