diff --git a/manifests/iface.pp b/manifests/iface.pp
index 94334f5..9eb49a8 100644
--- a/manifests/iface.pp
+++ b/manifests/iface.pp
@@ -1,5 +1,5 @@
-define interfaces::iface ( $family, $method, $options=[], $auto=0, $ifname="" ) {
-  if $ifname == "" {
+define interfaces::iface ( $family, $method, $options=[], $auto=0, $ifname='' ) {
+  if $ifname == '' {
     $_ifname = $name
   } else {
     $_ifname = $ifname