diff --git a/tacker/db/nfvo/vnffg_db.py b/tacker/db/nfvo/vnffg_db.py
index 6e5b51265..f208f5298 100644
--- a/tacker/db/nfvo/vnffg_db.py
+++ b/tacker/db/nfvo/vnffg_db.py
@@ -498,7 +498,7 @@ class VnffgPluginDbMixin(vnffg.VNFFGPluginBase, db_base.CommonDbMixin):
                     vnf_list = vnfm_plugin.get_vnfs(context,
                                                     {'vnfd_id': [vnfd_id]},
                                                     fields=['id'])
-                    if vnf_list is None:
+                    if len(vnf_list) == 0:
                         raise nfvo.VnffgInvalidMappingException(vnfd_name=vnfd)
                     else:
                         LOG.debug(_('Matching VNFs found %s'), vnf_list)