diff --git a/sys/netlink/netlink_snl.h b/sys/netlink/netlink_snl.h
--- a/sys/netlink/netlink_snl.h
+++ b/sys/netlink/netlink_snl.h
@@ -1109,20 +1109,22 @@
 #define snl_reserve_msg_object(_ns, _t)	((_t *)snl_reserve_msg_data_raw(_ns, sizeof(_t)))
 #define snl_reserve_msg_data(_ns, _sz, _t)	((_t *)snl_reserve_msg_data_raw(_ns, _sz))
 
-static inline void *
-_snl_reserve_msg_attr(struct snl_writer *nw, uint16_t nla_type, uint16_t sz)
+static inline struct nlattr *
+snl_reserve_msg_attr_raw(struct snl_writer *nw, uint16_t nla_type, uint16_t sz)
 {
-	sz += sizeof(struct nlattr);
+	struct nlattr *nla;
 
-	struct nlattr *nla = snl_reserve_msg_data(nw, sz, struct nlattr);
+	sz += sizeof(struct nlattr);
+	nla = snl_reserve_msg_data(nw, sz, struct nlattr);
 	if (__predict_false(nla == NULL))
 		return (NULL);
 	nla->nla_type = nla_type;
 	nla->nla_len = sz;
 
-	return ((void *)(nla + 1));
+	return (nla);
 }
-#define	snl_reserve_msg_attr(_ns, _at, _t)	((_t *)_snl_reserve_msg_attr(_ns, _at, sizeof(_t)))
+#define	snl_reserve_msg_attr(_ns, _at, _t)	\
+	((_t *)(snl_reserve_msg_attr_raw(_ns, _at, sizeof(_t)) + 1))
 
 static inline bool
 snl_add_msg_attr(struct snl_writer *nw, int attr_type, int attr_len, const void *data)