diff --git a/manifests/inspector/pxe_filter/dnsmasq.pp b/manifests/inspector/pxe_filter/dnsmasq.pp
index 31406efc..5af888ff 100644
--- a/manifests/inspector/pxe_filter/dnsmasq.pp
+++ b/manifests/inspector/pxe_filter/dnsmasq.pp
@@ -39,6 +39,10 @@ class ironic::inspector::pxe_filter::dnsmasq (
   include ironic::deps
   include ironic::inspector
 
+  if $::ironic::inspector::dnsmasq_dhcp_hostsdir == undef {
+    warning("The ironic::inspector::dnsmasq_dhcp_hostsdir parameter should be \
+configured properly to use dnsmasq PXE filter.")
+  }
   $hostsdir = pick($::ironic::inspector::dnsmasq_dhcp_hostsdir, $facts['os_service_default'])
 
   ironic_inspector_config {