diff --git a/manifests/proxydns.pp b/manifests/proxydns.pp
index 3eea98904..b1e313d18 100644
--- a/manifests/proxydns.pp
+++ b/manifests/proxydns.pp
@@ -35,10 +35,10 @@
   # puppet fact names are converted from ethX.X and ethX:X to ethX_X
   # so for alias and vlan interfaces we have to modify the name accordingly
   $interface_fact_name = regsubst($interface, '[.:]', '_')
-  $ip = getvar("::ipaddress_${interface_fact_name}")
+  $ip = fact("ipaddress_${interface_fact_name}")
 
-  unless is_ip_address($ip) {
-    fail("Could not get the ip address from fact ipaddress_${interface_fact_name}")
+  assert_type(Stdlib::Compat::Ipv4, $ip) |$expected, $actual| {
+    fail("Could not get a valid IP address from fact ipaddress_${interface_fact_name}: '${ip}' (${actual})")
   }
 
   if $reverse_zone {