diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 6e0adfefb9ed4..59c08997bfdfd 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -533,6 +533,7 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 	return -1;
 }
 
+#if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS)
 static size_t ctnetlink_proto_size(const struct nf_conn *ct)
 {
 	const struct nf_conntrack_l3proto *l3proto;
@@ -552,6 +553,7 @@ static size_t ctnetlink_proto_size(const struct nf_conn *ct)
 
 	return len + len4;
 }
+#endif
 
 static inline size_t ctnetlink_acct_size(const struct nf_conn *ct)
 {