diff --git a/firewall/manifests/init.pp b/firewall/manifests/init.pp
index e870c22..3a9a096 100644
--- a/firewall/manifests/init.pp
+++ b/firewall/manifests/init.pp
@@ -19,6 +19,13 @@
 #
 class firewall {
 
+    if ! $firewall_custom {
+        $firewall_custom = []
+    }
+    if ! $firewall_rules {
+        $firewall_rules = []
+    }
+
     case $operatingsystem {
 	centos,fedora: {
 	    include firewall::iptables