diff --git a/modules/observer/manifests/init.pp b/modules/observer/manifests/init.pp
index 563c3fc0..aabcc754 100644
--- a/modules/observer/manifests/init.pp
+++ b/modules/observer/manifests/init.pp
@@ -12,7 +12,7 @@
 # No parameters;
 #
 
-class observer($nameservers, $icmp_target, $dns_target) {
+class observer($nameservers, $icmp_target, $dns_target, $interface) {
 
   # Create directories for observer
   file { '/opt/observer':