diff --git a/manifests/init.pp b/manifests/init.pp
index d65d2d42ff10ee8bd8d1d3ec181693d871d0da4a..a620f330835cb9daebccccd2c0275b10499f0579 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -260,8 +260,8 @@ class network (
     if $ipv6_defaultgw =~ Stdlib::IP::Address::V6 {
       $manage_ipv6_defaultgw = $ipv6_defaultgw
     } else {
-      notify {"wrong IPv6 default gateway address: $ipv6_defaultgw":}
-      err ("wrong IPv6 default gateway address: $ipv6_defaultgw")
+      notify {"wrong IPv6 default gateway address: ${ipv6_defaultgw}":}
+      err ("wrong IPv6 default gateway address: ${ipv6_defaultgw}")
     }
   }
   if $ipv6_radvd_pidfile =~ Stdlib::Absolutepath {