diff --git a/extensions/libxt_pknock.c b/extensions/libxt_pknock.c
index 3e671a9..3e5f044 100644
--- a/extensions/libxt_pknock.c
+++ b/extensions/libxt_pknock.c
@@ -334,6 +334,7 @@ static void pknock_save(const void *ip, const struct xt_entry_match *match)
 static struct xtables_match pknock_match = {
 	.name		= "pknock",
 	.version	= XTABLES_VERSION,
+	.revision      = 1,
 	.family		= AF_INET,
 	.size		= XT_ALIGN(sizeof (struct ipt_pknock)),
 	.userspacesize	= XT_ALIGN(sizeof (struct ipt_pknock)),
diff --git a/extensions/xt_pknock.c b/extensions/xt_pknock.c
index 6bb13ca..15e043e 100644
--- a/extensions/xt_pknock.c
+++ b/extensions/xt_pknock.c
@@ -1076,6 +1076,7 @@ static void pknock_mt_destroy(const struct xt_mtdtor_param *par)
 
 static struct xt_match xt_pknock_mt_reg __read_mostly = {
 	.name		= "pknock",
+	.revision   = 1,
 	.family		= NFPROTO_IPV4,
 	.matchsize	= sizeof (struct ipt_pknock),
 	.match      = pknock_mt,