diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index 7e31777082de..04691edf50c2 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -623,7 +623,7 @@ static void nf_nat_move_storage(struct nf_conn *conntrack, void *old)
 	write_unlock_bh(&nf_nat_lock);
 }
 
-struct nf_ct_ext_type nat_extend = {
+static struct nf_ct_ext_type nat_extend __read_mostly = {
 	.len		= sizeof(struct nf_conn_nat),
 	.align		= __alignof__(struct nf_conn_nat),
 	.destroy	= nf_nat_cleanup_conntrack,
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 6d32399d64e1..dc352f509477 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -145,7 +145,7 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister);
 
-struct nf_ct_ext_type helper_extend = {
+static struct nf_ct_ext_type helper_extend __read_mostly = {
 	.len	= sizeof(struct nf_conn_help),
 	.align	= __alignof__(struct nf_conn_help),
 	.id	= NF_CT_EXT_HELPER,