diff --git a/Shorewall/action.DropSmurfs b/Shorewall/action.DropSmurfs
index 100daa2a1..476712898 100644
--- a/Shorewall/action.DropSmurfs
+++ b/Shorewall/action.DropSmurfs
@@ -16,6 +16,7 @@ DEFAULTS -
 ?BEGIN PERL;
 use strict;
 use Shorewall::Config qw(:DEFAULT F_IPV4 F_IPV6);
+use Shorewall::IPAddrs qw( IPv6_MULTICAST );
 use Shorewall::Chains;
 use Shorewall::Rules;