diff --git a/channeld/channel.c b/channeld/channel.c
index efbbc6dcf..81d18b502 100644
--- a/channeld/channel.c
+++ b/channeld/channel.c
@@ -259,7 +259,7 @@ static void gossip_in(struct peer *peer, const u8 *msg)
 	u8 *gossip;
 	u16 type;
 
-	if (!fromwire_gossip_send_gossip(msg, msg, NULL,
+	if (!fromwire_gossip_send_gossip(msg, msg,
 					 &peer->gossip_index, &gossip))
 		status_failed(STATUS_FAIL_GOSSIP_IO,
 			      "Got bad message from gossipd: %s",
@@ -335,7 +335,7 @@ static void send_announcement_signatures(struct peer *peer)
 			      strerror(errno));
 
 	msg = wire_sync_read(tmpctx, HSM_FD);
-	if (!msg || !fromwire_hsm_cannouncement_sig_reply(msg, NULL,
+	if (!msg || !fromwire_hsm_cannouncement_sig_reply(msg,
 					  &peer->announcement_node_sigs[LOCAL]))
 		status_failed(STATUS_FAIL_HSM_IO,
 			      "Reading cannouncement_sig_resp: %s",
@@ -399,7 +399,7 @@ static u8 *create_channel_update(const tal_t *ctx,
 			      strerror(errno));
 
 	msg = wire_sync_read(tmpctx, HSM_FD);
-	if (!msg || !fromwire_hsm_cupdate_sig_reply(ctx, msg, NULL, &cupdate))
+	if (!msg || !fromwire_hsm_cupdate_sig_reply(ctx, msg, &cupdate))
 		status_failed(STATUS_FAIL_HSM_IO,
 			      "Reading cupdate_sig_req: %s",
 			      strerror(errno));
@@ -450,7 +450,7 @@ static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
 		return;
 
 	peer->old_remote_per_commit = peer->remote_per_commit;
-	if (!fromwire_funding_locked(msg, NULL, &chanid,
+	if (!fromwire_funding_locked(msg, &chanid,
 				     &peer->remote_per_commit))
 		peer_failed(&peer->cs, peer->gossip_index,
 			    &peer->channel_id,
@@ -517,7 +517,7 @@ static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg
 {
 	struct channel_id chanid;
 
-	if (!fromwire_announcement_signatures(msg, NULL,
+	if (!fromwire_announcement_signatures(msg,
 					      &chanid,
 					      &peer->short_channel_ids[REMOTE],
 					      &peer->announcement_node_sigs[REMOTE],
@@ -568,7 +568,7 @@ static bool get_shared_secret(const struct htlc *htlc,
 		status_failed(STATUS_FAIL_HSM_IO, "Writing ecdh req");
 	msg = wire_sync_read(tmpctx, HSM_FD);
 	/* Gives all-zero shares_secret if it was invalid. */
-	if (!msg || !fromwire_hsm_ecdh_resp(msg, NULL, shared_secret))
+	if (!msg || !fromwire_hsm_ecdh_resp(msg, shared_secret))
 		status_failed(STATUS_FAIL_HSM_IO, "Reading ecdh response");
 	tal_free(tmpctx);
 
@@ -586,7 +586,7 @@ static void handle_peer_add_htlc(struct peer *peer, const u8 *msg)
 	enum channel_add_err add_err;
 	struct htlc *htlc;
 
-	if (!fromwire_update_add_htlc(msg, NULL, &channel_id, &id, &amount_msat,
+	if (!fromwire_update_add_htlc(msg, &channel_id, &id, &amount_msat,
 				      &payment_hash, &cltv_expiry,
 				      onion_routing_packet))
 		peer_failed(&peer->cs,
@@ -615,7 +615,7 @@ static void handle_peer_feechange(struct peer *peer, const u8 *msg)
 	struct channel_id channel_id;
 	u32 feerate;
 
-	if (!fromwire_update_fee(msg, NULL, &channel_id, &feerate)) {
+	if (!fromwire_update_fee(msg, &channel_id, &feerate)) {
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
 			    &peer->channel_id,
@@ -1163,7 +1163,7 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 						 peer->channel->view[LOCAL]
 						 .feerate_per_kw));
 
-	if (!fromwire_commitment_signed(tmpctx, msg, NULL,
+	if (!fromwire_commitment_signed(tmpctx, msg,
 					&channel_id, &commit_sig, &htlc_sigs))
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
@@ -1294,7 +1294,7 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 	tal_t *tmpctx = tal_tmpctx(msg);
 	const struct htlc **changed_htlcs = tal_arr(msg, const struct htlc *, 0);
 
-	if (!fromwire_revoke_and_ack(msg, NULL, &channel_id, &old_commit_secret,
+	if (!fromwire_revoke_and_ack(msg, &channel_id, &old_commit_secret,
 				     &next_per_commit)) {
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
@@ -1369,7 +1369,7 @@ static void handle_peer_fulfill_htlc(struct peer *peer, const u8 *msg)
 	struct preimage preimage;
 	enum channel_remove_err e;
 
-	if (!fromwire_update_fulfill_htlc(msg, NULL, &channel_id,
+	if (!fromwire_update_fulfill_htlc(msg, &channel_id,
 					  &id, &preimage)) {
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
@@ -1408,7 +1408,7 @@ static void handle_peer_fail_htlc(struct peer *peer, const u8 *msg)
 	u8 *reason;
 	struct htlc *htlc;
 
-	if (!fromwire_update_fail_htlc(msg, msg, NULL,
+	if (!fromwire_update_fail_htlc(msg, msg,
 				       &channel_id, &id, &reason)) {
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
@@ -1449,7 +1449,7 @@ static void handle_peer_fail_malformed_htlc(struct peer *peer, const u8 *msg)
 	struct htlc *htlc;
 	u8 *fail;
 
-	if (!fromwire_update_fail_malformed_htlc(msg, NULL, &channel_id, &id,
+	if (!fromwire_update_fail_malformed_htlc(msg, &channel_id, &id,
 						 &sha256_of_onion,
 						 &failure_code)) {
 		peer_failed(&peer->cs,
@@ -1517,7 +1517,7 @@ static void handle_pong(struct peer *peer, const u8 *pong)
 	u8 *ignored;
 
 	status_trace("Got pong!");
-	if (!fromwire_pong(pong, pong, NULL, &ignored))
+	if (!fromwire_pong(pong, pong, &ignored))
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
 			    &peer->channel_id,
@@ -1542,7 +1542,7 @@ static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
 	msg = create_channel_update(peer, peer, true);
 	wire_sync_write(GOSSIP_FD, take(msg));
 
-	if (!fromwire_shutdown(peer, shutdown, NULL, &channel_id, &scriptpubkey))
+	if (!fromwire_shutdown(peer, shutdown, &channel_id, &scriptpubkey))
 		peer_failed(&peer->cs,
 			    peer->gossip_index,
 			    &peer->channel_id,
@@ -1793,7 +1793,7 @@ static void peer_reconnect(struct peer *peer)
 	/* Read until they say something interesting */
 	while ((msg = channeld_read_peer_msg(peer)) == NULL);
 
-	if (!fromwire_channel_reestablish(msg, NULL, &channel_id,
+	if (!fromwire_channel_reestablish(msg, &channel_id,
 					  &next_local_commitment_number,
 					  &next_remote_revocation_number)) {
 		peer_failed(&peer->cs,
@@ -1951,7 +1951,7 @@ static void handle_funding_locked(struct peer *peer, const u8 *msg)
 {
 	struct pubkey next_per_commit_point;
 
-	if (!fromwire_channel_funding_locked(msg, NULL,
+	if (!fromwire_channel_funding_locked(msg,
 					     &peer->short_channel_ids[LOCAL]))
 		master_badmsg(WIRE_CHANNEL_FUNDING_LOCKED, msg);
 
@@ -2003,7 +2003,7 @@ static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
 		status_failed(STATUS_FAIL_MASTER_IO,
 			      "funding not locked for offer_htlc");
 
-	if (!fromwire_channel_offer_htlc(inmsg, NULL, &amount_msat,
+	if (!fromwire_channel_offer_htlc(inmsg, &amount_msat,
 					 &cltv_expiry, &payment_hash,
 					 onion_routing_packet))
 		master_badmsg(WIRE_CHANNEL_OFFER_HTLC, inmsg);
@@ -2073,7 +2073,7 @@ static void handle_feerates(struct peer *peer, const u8 *inmsg)
 {
 	u32 feerate;
 
-	if (!fromwire_channel_feerates(inmsg, NULL, &feerate,
+	if (!fromwire_channel_feerates(inmsg, &feerate,
 				       &peer->feerate_min,
 				       &peer->feerate_max))
 		master_badmsg(WIRE_CHANNEL_FEERATES, inmsg);
@@ -2104,7 +2104,7 @@ static void handle_preimage(struct peer *peer, const u8 *inmsg)
 	u64 id;
 	struct preimage preimage;
 
-	if (!fromwire_channel_fulfill_htlc(inmsg, NULL, &id, &preimage))
+	if (!fromwire_channel_fulfill_htlc(inmsg, &id, &preimage))
 		master_badmsg(WIRE_CHANNEL_FULFILL_HTLC, inmsg);
 
 	switch (channel_fulfill_htlc(peer->channel, REMOTE, id, &preimage)) {
@@ -2138,7 +2138,7 @@ static u8 *foreign_channel_update(const tal_t *ctx,
 	msg = towire_gossip_get_update(tmpctx, scid);
 	msg = gossipd_wait_sync_reply(tmpctx, peer, take(msg),
 				      WIRE_GOSSIP_GET_UPDATE_REPLY);
-	if (!fromwire_gossip_get_update_reply(ctx, msg, NULL, &update))
+	if (!fromwire_gossip_get_update_reply(ctx, msg, &update))
 		status_failed(STATUS_FAIL_GOSSIP_IO,
 			      "Invalid update reply");
 	tal_free(tmpctx);
@@ -2244,7 +2244,7 @@ static void handle_fail(struct peer *peer, const u8 *inmsg)
 	enum channel_remove_err e;
 	struct htlc *h;
 
-	if (!fromwire_channel_fail_htlc(inmsg, inmsg, NULL, &id, &errpkt,
+	if (!fromwire_channel_fail_htlc(inmsg, inmsg, &id, &errpkt,
 					&failcode, &scid))
 		master_badmsg(WIRE_CHANNEL_FAIL_HTLC, inmsg);
 
@@ -2303,7 +2303,7 @@ static void handle_ping_cmd(struct peer *peer, const u8 *inmsg)
 	u16 num_pong_bytes, ping_len;
 	u8 *ping;
 
-	if (!fromwire_channel_ping(inmsg, NULL, &num_pong_bytes, &ping_len))
+	if (!fromwire_channel_ping(inmsg, &num_pong_bytes, &ping_len))
 		master_badmsg(WIRE_CHANNEL_PING, inmsg);
 
 	ping = make_ping(peer, num_pong_bytes, ping_len);
@@ -2332,7 +2332,7 @@ static void handle_shutdown_cmd(struct peer *peer, const u8 *inmsg)
 {
 	u8 *scriptpubkey;
 
-	if (!fromwire_channel_send_shutdown(peer, inmsg, NULL, &scriptpubkey))
+	if (!fromwire_channel_send_shutdown(peer, inmsg, &scriptpubkey))
 		master_badmsg(WIRE_CHANNEL_SEND_SHUTDOWN, inmsg);
 
 	/* We can't send this until commit (if any) is done, so start timer<. */
@@ -2448,7 +2448,7 @@ static void init_channel(struct peer *peer)
 	status_setup_sync(MASTER_FD);
 
 	msg = wire_sync_read(peer, MASTER_FD);
-	if (!fromwire_channel_init(peer, msg, NULL,
+	if (!fromwire_channel_init(peer, msg,
 				   &peer->chain_hash,
 				   &funding_txid, &funding_txout,
 				   &funding_satoshi,
diff --git a/closingd/closing.c b/closingd/closing.c
index 155824c65..cfbd199a9 100644
--- a/closingd/closing.c
+++ b/closingd/closing.c
@@ -123,7 +123,7 @@ static void do_reconnect(struct crypto_state *cs,
 	/* Wait for them to say something interesting */
 	msg = closing_read_peer_msg(tmpctx, cs, gossip_index, channel_id);
 
-	if (!fromwire_channel_reestablish(msg, NULL, &their_channel_id,
+	if (!fromwire_channel_reestablish(msg, &their_channel_id,
 					  &next_local_commitment_number,
 					  &next_remote_revocation_number)) {
 		peer_failed(cs, gossip_index, channel_id,
@@ -218,7 +218,7 @@ static void tell_master_their_offer(u64 their_offer,
 
 	/* Wait for master to ack, to make sure it's in db. */
 	msg = wire_sync_read(NULL, REQ_FD);
-	if (!fromwire_closing_received_signature_reply(msg,NULL))
+	if (!fromwire_closing_received_signature_reply(msg))
 		master_badmsg(WIRE_CLOSING_RECEIVED_SIGNATURE_REPLY, msg);
 	tal_free(msg);
 }
@@ -267,7 +267,7 @@ static uint64_t receive_offer(struct crypto_state *cs,
 			msg = tal_free(msg);
 	} while (!msg);
 
-	if (!fromwire_closing_signed(msg, NULL, &their_channel_id,
+	if (!fromwire_closing_signed(msg, &their_channel_id,
 				     &received_fee, &their_sig))
 		peer_failed(cs, gossip_index, channel_id,
 			    "Expected closing_signed: %s",
@@ -463,7 +463,7 @@ int main(int argc, char *argv[])
 	status_setup_sync(REQ_FD);
 
 	msg = wire_sync_read(ctx, REQ_FD);
-	if (!fromwire_closing_init(ctx, msg, NULL,
+	if (!fromwire_closing_init(ctx, msg,
 				   &cs, &gossip_index, &seed,
 				   &funding_txid, &funding_txout,
 				   &funding_satoshi,
diff --git a/common/ping.c b/common/ping.c
index 519f9974d..dad7b9eca 100644
--- a/common/ping.c
+++ b/common/ping.c
@@ -6,7 +6,7 @@ bool check_ping_make_pong(const tal_t *ctx, const u8 *ping, u8 **pong)
 	u16 num_pong_bytes;
 	u8 *ignored;
 
-	if (!fromwire_ping(ctx, ping, NULL, &num_pong_bytes, &ignored))
+	if (!fromwire_ping(ctx, ping, &num_pong_bytes, &ignored))
 		return false;
 	tal_free(ignored);
 
diff --git a/common/wire_error.c b/common/wire_error.c
index 9ed3d2c33..a9c21494b 100644
--- a/common/wire_error.c
+++ b/common/wire_error.c
@@ -58,7 +58,7 @@ char *sanitize_error(const tal_t *ctx, const u8 *errmsg,
 	if (!channel_id)
 		channel_id = &dummy;
 
-	if (!fromwire_error(ctx, errmsg, NULL, channel_id, &data))
+	if (!fromwire_error(ctx, errmsg, channel_id, &data))
 		return tal_fmt(ctx, "Invalid ERROR message '%s'",
 			       tal_hex(ctx, errmsg));
 
diff --git a/gossipd/gossip.c b/gossipd/gossip.c
index 31ecafd78..9e1d4a5c7 100644
--- a/gossipd/gossip.c
+++ b/gossipd/gossip.c
@@ -314,7 +314,7 @@ static bool is_all_channel_error(const u8 *msg)
 	struct channel_id channel_id;
 	u8 *data;
 
-	if (!fromwire_error(msg, msg, NULL, &channel_id, &data))
+	if (!fromwire_error(msg, msg, &channel_id, &data))
 		return false;
 	tal_free(data);
 	return channel_id_is_all(&channel_id);
@@ -332,7 +332,7 @@ static struct io_plan *peer_init_received(struct io_conn *conn,
 					  struct peer *peer,
 					  u8 *msg)
 {
-	if (!fromwire_init(peer, msg, NULL, &peer->gfeatures, &peer->lfeatures)){
+	if (!fromwire_init(peer, msg, &peer->gfeatures, &peer->lfeatures)){
 		status_trace("peer %s bad fromwire_init '%s', closing",
 			     type_to_string(trc, struct pubkey, &peer->id),
 			     tal_hex(trc, msg));
@@ -449,7 +449,7 @@ static void send_node_announcement(struct daemon *daemon)
 		status_failed(STATUS_FAIL_MASTER_IO, "Could not write to HSM: %s", strerror(errno));
 
 	msg = wire_sync_read(tmpctx, HSM_FD);
-	if (!fromwire_hsm_node_announcement_sig_reply(msg, NULL, &sig))
+	if (!fromwire_hsm_node_announcement_sig_reply(msg, &sig))
 		status_failed(STATUS_FAIL_MASTER_IO, "HSM returned an invalid node_announcement sig");
 
 	/* We got the signature for out provisional node_announcement back
@@ -505,7 +505,7 @@ static void handle_pong(struct peer *peer, const u8 *pong)
 	u8 *ignored;
 
 	status_trace("Got pong!");
-	if (!fromwire_pong(pong, pong, NULL, &ignored)) {
+	if (!fromwire_pong(pong, pong, &ignored)) {
 		peer_error(peer, "Bad pong");
 		return;
 	}
@@ -720,7 +720,7 @@ static void handle_get_update(struct peer *peer, const u8 *msg)
 	size_t i;
 	const u8 *update;
 
-	if (!fromwire_gossip_get_update(msg, NULL, &schanid)) {
+	if (!fromwire_gossip_get_update(msg, &schanid)) {
 		status_trace("peer %s sent bad gossip_get_update %s",
 			     type_to_string(trc, struct pubkey, &peer->id),
 			     tal_hex(trc, msg));
@@ -771,7 +771,7 @@ static void handle_local_add_channel(struct peer *peer, u8 *msg)
 	struct routing_channel *chan;
 
 	if (!fromwire_gossip_local_add_channel(
-		msg, NULL, &scid, &chain_hash, &remote_node_id, &flags,
+		msg, &scid, &chain_hash, &remote_node_id, &flags,
 		&cltv_expiry_delta, &htlc_minimum_msat, &fee_base_msat,
 		&fee_proportional_millionths)) {
 		status_trace("Unable to parse local_add_channel message: %s", tal_hex(msg, msg));
@@ -1006,7 +1006,7 @@ static struct io_plan *hand_back_peer(struct io_conn *conn,
 	struct returning_peer *rpeer = tal(daemon, struct returning_peer);
 
 	rpeer->daemon = daemon;
-	if (!fromwire_gossipctl_hand_back_peer(msg, msg, NULL,
+	if (!fromwire_gossipctl_hand_back_peer(msg, msg,
 					       &rpeer->id, &rpeer->cs,
 					       &rpeer->gossip_index,
 					       &rpeer->inner_msg))
@@ -1022,7 +1022,7 @@ static struct io_plan *release_peer(struct io_conn *conn, struct daemon *daemon,
 	struct pubkey id;
  	struct peer *peer;
 
-	if (!fromwire_gossipctl_release_peer(msg, NULL, &id))
+	if (!fromwire_gossipctl_release_peer(msg, &id))
 		master_badmsg(WIRE_GOSSIPCTL_RELEASE_PEER, msg);
 
 	peer = find_peer(daemon, &id);
@@ -1055,7 +1055,7 @@ static struct io_plan *getroute_req(struct io_conn *conn, struct daemon *daemon,
 	u8 *out;
 	struct route_hop *hops;
 
-	fromwire_gossip_getroute_request(msg, NULL, &source, &destination,
+	fromwire_gossip_getroute_request(msg, &source, &destination,
 					 &msatoshi, &riskfactor, &final_cltv);
 	status_trace("Trying to find a route from %s to %s for %d msatoshi",
 		     pubkey_to_hexstr(tmpctx, &source),
@@ -1081,7 +1081,7 @@ static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daem
 	struct node_map_iter i;
 	struct short_channel_id *scid;
 
-	fromwire_gossip_getchannels_request(msg, msg, NULL, &scid);
+	fromwire_gossip_getchannels_request(msg, msg, &scid);
 
 	entries = tal_arr(tmpctx, struct gossip_getchannels_entry, num_chans);
 	n = node_map_first(daemon->rstate->nodes, &i);
@@ -1145,7 +1145,7 @@ static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
 	const struct gossip_getnodes_entry **nodes;
 	struct pubkey *ids;
 
-	fromwire_gossip_getnodes_request(tmpctx, msg, NULL, &ids);
+	fromwire_gossip_getnodes_request(tmpctx, msg, &ids);
 
 	nodes = tal_arr(tmpctx, const struct gossip_getnodes_entry *, 0);
 	if (ids) {
@@ -1176,7 +1176,7 @@ static struct io_plan *ping_req(struct io_conn *conn, struct daemon *daemon,
 	struct peer *peer;
 	u8 *ping;
 
-	if (!fromwire_gossip_ping(msg, NULL, &id, &num_pong_bytes, &len))
+	if (!fromwire_gossip_ping(msg, &id, &num_pong_bytes, &len))
 		master_badmsg(WIRE_GOSSIP_PING, msg);
 
 	peer = find_peer(daemon, &id);
@@ -1251,7 +1251,6 @@ static void gossip_send_keepalive_update(struct routing_state *rstate,
 					 struct node_connection *nc)
 {
 	tal_t *tmpctx = tal_tmpctx(nc);
-	size_t plen = tal_len(nc->channel_update);
 	secp256k1_ecdsa_signature sig;
 	struct bitcoin_blkid chain_hash;
 	struct short_channel_id scid;
@@ -1262,7 +1261,7 @@ static void gossip_send_keepalive_update(struct routing_state *rstate,
 
 	/* Parse old update */
 	if (!fromwire_channel_update(
-		nc->channel_update, &plen, &sig, &chain_hash, &scid, &timestamp,
+		nc->channel_update, &sig, &chain_hash, &scid, &timestamp,
 		&flags, &cltv_expiry_delta, &htlc_minimum_msat, &fee_base_msat,
 		&fee_proportional_millionths)) {
 		status_failed(
@@ -1284,7 +1283,7 @@ static void gossip_send_keepalive_update(struct routing_state *rstate,
 	}
 
 	msg = wire_sync_read(tmpctx, HSM_FD);
-	if (!msg || !fromwire_hsm_cupdate_sig_reply(tmpctx, msg, NULL, &update)) {
+	if (!msg || !fromwire_hsm_cupdate_sig_reply(tmpctx, msg, &update)) {
 		status_failed(STATUS_FAIL_HSM_IO,
 			      "Reading cupdate_sig_req: %s",
 			      strerror(errno));
@@ -1502,7 +1501,7 @@ static struct io_plan *gossip_init(struct daemon_conn *master,
 	u16 port;
 
 	if (!fromwire_gossipctl_init(
-		daemon, msg, NULL, &daemon->broadcast_interval, &chain_hash,
+		daemon, msg, &daemon->broadcast_interval, &chain_hash,
 		&daemon->id, &port, &daemon->globalfeatures,
 		&daemon->localfeatures, &daemon->wireaddrs, daemon->rgb,
 		daemon->alias, &daemon->update_channel_interval)) {
@@ -1526,7 +1525,7 @@ static struct io_plan *resolve_channel_req(struct io_conn *conn,
 	struct node_connection *nc;
 	struct pubkey *keys;
 
-	if (!fromwire_gossip_resolve_channel_request(msg, NULL, &scid))
+	if (!fromwire_gossip_resolve_channel_request(msg, &scid))
 		master_badmsg(WIRE_GOSSIP_RESOLVE_CHANNEL_REQUEST, msg);
 
 	nc = get_connection_by_scid(daemon->rstate, &scid, 0);
@@ -1734,7 +1733,7 @@ static struct io_plan *reach_peer(struct io_conn *conn,
 {
 	struct pubkey id;
 
-	if (!fromwire_gossipctl_reach_peer(msg, NULL, &id))
+	if (!fromwire_gossipctl_reach_peer(msg, &id))
 		master_badmsg(WIRE_GOSSIPCTL_REACH_PEER, msg);
 
 	/* Master can't check this itself, because that's racy. */
@@ -1752,7 +1751,7 @@ static struct io_plan *addr_hint(struct io_conn *conn,
 {
 	struct addrhint *a = tal(daemon, struct addrhint);
 
-	if (!fromwire_gossipctl_peer_addrhint(msg, NULL, &a->id, &a->addr))
+	if (!fromwire_gossipctl_peer_addrhint(msg, &a->id, &a->addr))
 		master_badmsg(WIRE_GOSSIPCTL_PEER_ADDRHINT, msg);
 
 	/* Replace any old one. */
@@ -1773,7 +1772,7 @@ static struct io_plan *get_peers(struct io_conn *conn,
 	struct wireaddr *wireaddr = tal_arr(conn, struct wireaddr, n);
 	struct pubkey *specific_id = NULL;
 
-	if (!fromwire_gossip_getpeers_request(msg, msg, NULL, &specific_id))
+	if (!fromwire_gossip_getpeers_request(msg, msg, &specific_id))
 		master_badmsg(WIRE_GOSSIPCTL_PEER_ADDRHINT, msg);
 
 	list_for_each(&daemon->peers, peer, list) {
@@ -1798,7 +1797,7 @@ static struct io_plan *handle_txout_reply(struct io_conn *conn,
 	struct short_channel_id scid;
 	u8 *outscript;
 
-	if (!fromwire_gossip_get_txout_reply(msg, msg, NULL, &scid, &outscript))
+	if (!fromwire_gossip_get_txout_reply(msg, msg, &scid, &outscript))
 		master_badmsg(WIRE_GOSSIP_GET_TXOUT_REPLY, msg);
 
 	if (handle_pending_cannouncement(daemon->rstate, &scid, outscript))
@@ -1821,7 +1820,7 @@ static struct io_plan *handle_disable_channel(struct io_conn *conn,
 	secp256k1_ecdsa_signature sig;
 	u64 htlc_minimum_msat;
 
-	if (!fromwire_gossip_disable_channel(msg, NULL, &scid, &direction, &active) ) {
+	if (!fromwire_gossip_disable_channel(msg, &scid, &direction, &active) ) {
 		status_trace("Unable to parse %s",
 			     gossip_wire_type_name(fromwire_peektype(msg)));
 		goto fail;
@@ -1853,7 +1852,7 @@ static struct io_plan *handle_disable_channel(struct io_conn *conn,
 	}
 
 	if (!fromwire_channel_update(
-		nc->channel_update, NULL, &sig, &chain_hash, &scid, &timestamp,
+		nc->channel_update, &sig, &chain_hash, &scid, &timestamp,
 		&flags, &cltv_expiry_delta, &htlc_minimum_msat, &fee_base_msat,
 		&fee_proportional_millionths)) {
 		status_failed(
@@ -1879,7 +1878,7 @@ static struct io_plan *handle_disable_channel(struct io_conn *conn,
 	}
 
 	msg = wire_sync_read(tmpctx, HSM_FD);
-	if (!msg || !fromwire_hsm_cupdate_sig_reply(tmpctx, msg, NULL, &msg)) {
+	if (!msg || !fromwire_hsm_cupdate_sig_reply(tmpctx, msg, &msg)) {
 		status_failed(STATUS_FAIL_HSM_IO,
 			      "Reading cupdate_sig_req: %s",
 			      strerror(errno));
@@ -1901,7 +1900,7 @@ static struct io_plan *handle_routing_failure(struct io_conn *conn,
 	u8 *channel_update;
 
 	if (!fromwire_gossip_routing_failure(msg,
-					     msg, NULL,
+					     msg,
 					     &erring_node,
 					     &erring_channel,
 					     &failcode,
@@ -1923,7 +1922,7 @@ handle_mark_channel_unroutable(struct io_conn *conn,
 {
 	struct short_channel_id channel;
 
-	if (!fromwire_gossip_mark_channel_unroutable(msg, NULL, &channel))
+	if (!fromwire_gossip_mark_channel_unroutable(msg, &channel))
 		master_badmsg(WIRE_GOSSIP_MARK_CHANNEL_UNROUTABLE, msg);
 
 	mark_channel_unroutable(daemon->rstate, &channel);
diff --git a/gossipd/routing.c b/gossipd/routing.c
index fd16bd494..c77c36b07 100644
--- a/gossipd/routing.c
+++ b/gossipd/routing.c
@@ -648,7 +648,7 @@ const struct short_channel_id *handle_channel_announcement(
 					announce, tal_len(announce), 0);
 	pending->update_timestamps[0] = pending->update_timestamps[1] = 0;
 
-	if (!fromwire_channel_announcement(pending, pending->announce, NULL,
+	if (!fromwire_channel_announcement(pending, pending->announce,
 					   &node_signature_1,
 					   &node_signature_2,
 					   &bitcoin_signature_1,
@@ -880,7 +880,7 @@ void handle_channel_update(struct routing_state *rstate, const u8 *update)
 	size_t len = tal_len(update);
 
 	serialized = tal_dup_arr(tmpctx, u8, update, len, 0);
-	if (!fromwire_channel_update(serialized, NULL, &signature,
+	if (!fromwire_channel_update(serialized, &signature,
 				     &chain_hash, &short_channel_id,
 				     &timestamp, &flags, &expiry,
 				     &htlc_minimum_msat, &fee_base_msat,
@@ -1025,7 +1025,7 @@ void handle_node_announcement(
 	size_t len = tal_len(node_ann);
 
 	serialized = tal_dup_arr(tmpctx, u8, node_ann, len, 0);
-	if (!fromwire_node_announcement(tmpctx, serialized, NULL,
+	if (!fromwire_node_announcement(tmpctx, serialized,
 					&signature, &features, &timestamp,
 					&node_id, rgb_color, alias,
 					&addresses)) {
diff --git a/gossipd/test/run-bench-find_route.c b/gossipd/test/run-bench-find_route.c
index a474b7c94..2714d194a 100644
--- a/gossipd/test/run-bench-find_route.c
+++ b/gossipd/test/run-bench-find_route.c
@@ -56,13 +56,13 @@ struct broadcast_state *new_broadcast_state(tal_t *ctx UNNEEDED)
 
 /* AUTOGENERATED MOCKS START */
 /* Generated stub for fromwire_channel_announcement */
-bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
+bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
 { fprintf(stderr, "fromwire_channel_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_channel_update */
-bool fromwire_channel_update(const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
+bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
 { fprintf(stderr, "fromwire_channel_update called!\n"); abort(); }
 /* Generated stub for fromwire_node_announcement */
-bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
+bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
 { fprintf(stderr, "fromwire_node_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_peektype */
 int fromwire_peektype(const u8 *cursor UNNEEDED)
diff --git a/gossipd/test/run-find_route-specific.c b/gossipd/test/run-find_route-specific.c
index 884f568a8..eac0ae878 100644
--- a/gossipd/test/run-find_route-specific.c
+++ b/gossipd/test/run-find_route-specific.c
@@ -20,13 +20,13 @@ struct broadcast_state *new_broadcast_state(tal_t *ctx UNNEEDED)
 
 /* AUTOGENERATED MOCKS START */
 /* Generated stub for fromwire_channel_announcement */
-bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
+bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
 { fprintf(stderr, "fromwire_channel_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_channel_update */
-bool fromwire_channel_update(const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
+bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
 { fprintf(stderr, "fromwire_channel_update called!\n"); abort(); }
 /* Generated stub for fromwire_node_announcement */
-bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
+bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
 { fprintf(stderr, "fromwire_node_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_peektype */
 int fromwire_peektype(const u8 *cursor UNNEEDED)
diff --git a/gossipd/test/run-find_route.c b/gossipd/test/run-find_route.c
index 86c6c613c..52d2534ee 100644
--- a/gossipd/test/run-find_route.c
+++ b/gossipd/test/run-find_route.c
@@ -18,13 +18,13 @@ void status_fmt(enum log_level level, const char *fmt, ...)
 
 /* AUTOGENERATED MOCKS START */
 /* Generated stub for fromwire_channel_announcement */
-bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
+bool fromwire_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *node_signature_1 UNNEEDED, secp256k1_ecdsa_signature *node_signature_2 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_1 UNNEEDED, secp256k1_ecdsa_signature *bitcoin_signature_2 UNNEEDED, u8 **features UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, struct pubkey *node_id_1 UNNEEDED, struct pubkey *node_id_2 UNNEEDED, struct pubkey *bitcoin_key_1 UNNEEDED, struct pubkey *bitcoin_key_2 UNNEEDED)
 { fprintf(stderr, "fromwire_channel_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_channel_update */
-bool fromwire_channel_update(const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
+bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, struct bitcoin_blkid *chain_hash UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED, u32 *timestamp UNNEEDED, u16 *flags UNNEEDED, u16 *cltv_expiry_delta UNNEEDED, u64 *htlc_minimum_msat UNNEEDED, u32 *fee_base_msat UNNEEDED, u32 *fee_proportional_millionths UNNEEDED)
 { fprintf(stderr, "fromwire_channel_update called!\n"); abort(); }
 /* Generated stub for fromwire_node_announcement */
-bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
+bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
 { fprintf(stderr, "fromwire_node_announcement called!\n"); abort(); }
 /* Generated stub for fromwire_peektype */
 int fromwire_peektype(const u8 *cursor UNNEEDED)
diff --git a/hsmd/client.c b/hsmd/client.c
index 981329f24..c631f826f 100644
--- a/hsmd/client.c
+++ b/hsmd/client.c
@@ -12,15 +12,13 @@ void hsm_setup(int fd)
 bool hsm_do_ecdh(struct secret *ss, const struct pubkey *point)
 {
 	u8 *req = towire_hsm_ecdh_req(NULL, point), *resp;
-	size_t len;
 
 	if (!wire_sync_write(hsm_fd, req))
 		goto fail;
 	resp = wire_sync_read(req, hsm_fd);
 	if (!resp)
 		goto fail;
-	len = tal_count(resp);
-	if (!fromwire_hsm_ecdh_resp(resp, &len, ss))
+	if (!fromwire_hsm_ecdh_resp(resp, ss))
 		goto fail;
 	tal_free(req);
 	return true;
diff --git a/hsmd/hsm.c b/hsmd/hsm.c
index 2fcd76d59..8f1a8ed57 100644
--- a/hsmd/hsm.c
+++ b/hsmd/hsm.c
@@ -123,7 +123,7 @@ static struct io_plan *handle_ecdh(struct io_conn *conn, struct daemon_conn *dc)
 	struct pubkey point;
 	struct secret ss;
 
-	if (!fromwire_hsm_ecdh_req(dc->msg_in, NULL, &point)) {
+	if (!fromwire_hsm_ecdh_req(dc->msg_in, &point)) {
 		daemon_conn_send(c->master,
 				 take(towire_hsmstatus_client_bad_request(c,
 								&c->id,
@@ -160,7 +160,7 @@ static struct io_plan *handle_cannouncement_sig(struct io_conn *conn,
 	u8 *ca;
 	struct pubkey bitcoin_id;
 
-	if (!fromwire_hsm_cannouncement_sig_req(ctx, dc->msg_in, NULL,
+	if (!fromwire_hsm_cannouncement_sig_req(ctx, dc->msg_in,
 						&bitcoin_id, &ca)) {
 		status_broken("Failed to parse cannouncement_sig_req: %s",
 			      tal_hex(trc, dc->msg_in));
@@ -202,14 +202,14 @@ static struct io_plan *handle_channel_update_sig(struct io_conn *conn,
 	struct bitcoin_blkid chain_hash;
 	u8 *cu;
 
-	if (!fromwire_hsm_cupdate_sig_req(tmpctx, dc->msg_in, NULL, &cu)) {
+	if (!fromwire_hsm_cupdate_sig_req(tmpctx, dc->msg_in, &cu)) {
 		status_broken("Failed to parse %s: %s",
 			      hsm_client_wire_type_name(fromwire_peektype(dc->msg_in)),
 			      tal_hex(trc, dc->msg_in));
 		return io_close(conn);
 	}
 
-	if (!fromwire_channel_update(cu, NULL, &sig, &chain_hash,
+	if (!fromwire_channel_update(cu, &sig, &chain_hash,
 				     &scid, &timestamp, &flags,
 				     &cltv_expiry_delta, &htlc_minimum_msat,
 				     &fee_base_msat, &fee_proportional_mill)) {
@@ -522,7 +522,7 @@ static void init_hsm(struct daemon_conn *master, const u8 *msg)
 {
 	bool new;
 
-	if (!fromwire_hsm_init(msg, NULL, &new))
+	if (!fromwire_hsm_init(msg, &new))
 		master_badmsg(WIRE_HSM_INIT, msg);
 
 	if (new)
@@ -539,7 +539,7 @@ static void pass_client_hsmfd(struct daemon_conn *master, const u8 *msg)
 	u64 capabilities;
 	struct pubkey id;
 
-	if (!fromwire_hsm_client_hsmfd(msg, NULL, &id, &capabilities))
+	if (!fromwire_hsm_client_hsmfd(msg, &id, &capabilities))
 		master_badmsg(WIRE_HSM_CLIENT_HSMFD, msg);
 
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) != 0)
@@ -620,7 +620,7 @@ static void sign_funding_tx(struct daemon_conn *master, const u8 *msg)
 	u8 **scriptSigs;
 
 	/* FIXME: Check fee is "reasonable" */
-	if (!fromwire_hsm_sign_funding(tmpctx, msg, NULL,
+	if (!fromwire_hsm_sign_funding(tmpctx, msg,
 				       &satoshi_out, &change_out,
 				       &change_keyindex, &local_pubkey,
 				       &remote_pubkey, &utxomap))
@@ -687,7 +687,7 @@ static void sign_withdrawal_tx(struct daemon_conn *master, const u8 *msg)
 	struct pubkey changekey;
 	u8 *scriptpubkey;
 
-	if (!fromwire_hsm_sign_withdrawal(tmpctx, msg, NULL, &satoshi_out,
+	if (!fromwire_hsm_sign_withdrawal(tmpctx, msg, &satoshi_out,
 					  &change_out, &change_keyindex,
 					  &scriptpubkey, &utxos)) {
 		status_broken("Failed to parse sign_withdrawal: %s",
@@ -758,7 +758,7 @@ static void sign_invoice(struct daemon_conn *master, const u8 *msg)
 	struct hash_u5 hu5;
 	struct privkey node_pkey;
 
-	if (!fromwire_hsm_sign_invoice(tmpctx, msg, NULL, &u5bytes, &hrpu8)) {
+	if (!fromwire_hsm_sign_invoice(tmpctx, msg, &u5bytes, &hrpu8)) {
 		status_broken("Failed to parse sign_invoice: %s",
 			      tal_hex(trc, msg));
 		return;
@@ -798,7 +798,7 @@ static void sign_node_announcement(struct daemon_conn *master, const u8 *msg)
 	u8 *reply;
 	u8 *ann;
 
-	if (!fromwire_hsm_node_announcement_sig_req(msg, msg, NULL, &ann)) {
+	if (!fromwire_hsm_node_announcement_sig_req(msg, msg, &ann)) {
 		status_failed(STATUS_FAIL_GOSSIP_IO,
 			      "Failed to parse node_announcement_sig_req: %s",
 			     tal_hex(trc, msg));
diff --git a/lightningd/channel_control.c b/lightningd/channel_control.c
index 7e88ac7ff..83a83556a 100644
--- a/lightningd/channel_control.c
+++ b/lightningd/channel_control.c
@@ -23,7 +23,7 @@ static void peer_got_funding_locked(struct channel *channel, const u8 *msg)
 {
 	struct pubkey next_per_commitment_point;
 
-	if (!fromwire_channel_got_funding_locked(msg, NULL,
+	if (!fromwire_channel_got_funding_locked(msg,
 						 &next_per_commitment_point)) {
 		channel_internal_error(channel,
 				       "bad channel_got_funding_locked %s",
@@ -47,7 +47,7 @@ static void peer_got_shutdown(struct channel *channel, const u8 *msg)
 	u8 *scriptpubkey;
 	struct lightningd *ld = channel->peer->ld;
 
-	if (!fromwire_channel_got_shutdown(channel, msg, NULL, &scriptpubkey)) {
+	if (!fromwire_channel_got_shutdown(channel, msg, &scriptpubkey)) {
 		channel_internal_error(channel, "bad channel_got_shutdown %s",
 				       tal_hex(msg, msg));
 		return;
@@ -132,7 +132,7 @@ static void peer_start_closingd_after_shutdown(struct channel *channel,
 	/* We expect 2 fds. */
 	assert(tal_count(fds) == 2);
 
-	if (!fromwire_channel_shutdown_complete(msg, NULL, &cs, &gossip_index)) {
+	if (!fromwire_channel_shutdown_complete(msg, &cs, &gossip_index)) {
 		channel_internal_error(channel, "bad shutdown_complete: %s",
 				       tal_hex(msg, msg));
 		return;
@@ -225,7 +225,7 @@ bool peer_start_channeld(struct channel *channel,
 		fatal("Could not write to HSM: %s", strerror(errno));
 
 	msg = hsm_sync_read(tmpctx, ld);
-	if (!fromwire_hsm_client_hsmfd_reply(msg, NULL))
+	if (!fromwire_hsm_client_hsmfd_reply(msg))
 		fatal("Bad reply from HSM: %s", tal_hex(tmpctx, msg));
 
 	hsmfd = fdpass_recv(ld->hsm_fd);
diff --git a/lightningd/closing_control.c b/lightningd/closing_control.c
index 264403115..1cece38f7 100644
--- a/lightningd/closing_control.c
+++ b/lightningd/closing_control.c
@@ -74,7 +74,7 @@ static void peer_received_closing_signature(struct channel *channel,
 	struct bitcoin_tx *tx;
 	struct lightningd *ld = channel->peer->ld;
 
-	if (!fromwire_closing_received_signature(msg, msg, NULL, &sig, &tx)) {
+	if (!fromwire_closing_received_signature(msg, msg, &sig, &tx)) {
 		channel_internal_error(channel, "Bad closing_received_signature %s",
 				       tal_hex(msg, msg));
 		return;
@@ -97,7 +97,7 @@ static void peer_closing_complete(struct channel *channel, const u8 *msg)
 	/* FIXME: We should save this, to return to gossipd */
 	u64 gossip_index;
 
-	if (!fromwire_closing_complete(msg, NULL, &gossip_index)) {
+	if (!fromwire_closing_complete(msg, &gossip_index)) {
 		channel_internal_error(channel, "Bad closing_complete %s",
 				       tal_hex(msg, msg));
 		return;
diff --git a/lightningd/connect_control.c b/lightningd/connect_control.c
index 8583cbfa0..877f9bf06 100644
--- a/lightningd/connect_control.c
+++ b/lightningd/connect_control.c
@@ -70,7 +70,7 @@ void peer_connection_failed(struct lightningd *ld, const u8 *msg)
 	bool addr_unknown;
 	char *error;
 
-	if (!fromwire_gossip_peer_connection_failed(msg, NULL, &id, &timediff,
+	if (!fromwire_gossip_peer_connection_failed(msg, &id, &timediff,
 						    &attempts, &addr_unknown))
 		fatal(
 		    "Gossip gave bad GOSSIP_PEER_CONNECTION_FAILED message %s",
@@ -94,7 +94,7 @@ void peer_already_connected(struct lightningd *ld, const u8 *msg)
 {
 	struct pubkey id;
 
-	if (!fromwire_gossip_peer_already_connected(msg, NULL, &id))
+	if (!fromwire_gossip_peer_already_connected(msg, &id))
 		fatal("Gossip gave bad GOSSIP_PEER_ALREADY_CONNECTED message %s",
 		      tal_hex(msg, msg));
 
diff --git a/lightningd/dev_ping.c b/lightningd/dev_ping.c
index 7fdb5d8e0..d7b96a6a3 100644
--- a/lightningd/dev_ping.c
+++ b/lightningd/dev_ping.c
@@ -17,9 +17,9 @@ static void ping_reply(struct subd *subd, const u8 *msg, const int *fds,
 
 	log_debug(subd->ld->log, "Got ping reply!");
 	if (streq(subd->name, "lightning_channeld"))
-		ok = fromwire_channel_ping_reply(msg, NULL, &totlen);
+		ok = fromwire_channel_ping_reply(msg, &totlen);
 	else
-		ok = fromwire_gossip_ping_reply(msg, NULL, &sent, &totlen);
+		ok = fromwire_gossip_ping_reply(msg, &sent, &totlen);
 
 	if (!ok)
 		command_fail(cmd, "Bad reply message");
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index b199a0dd6..594fbd1bd 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -34,7 +34,7 @@ static void peer_nongossip(struct subd *gossip, const u8 *msg,
 	u8 *gfeatures, *lfeatures, *in_pkt;
 	u64 gossip_index;
 
-	if (!fromwire_gossip_peer_nongossip(msg, msg, NULL,
+	if (!fromwire_gossip_peer_nongossip(msg, msg,
 					    &id, &addr, &cs, &gossip_index,
 					    &gfeatures,
 					    &lfeatures,
@@ -79,7 +79,7 @@ static void get_txout(struct subd *gossip, const u8 *msg)
 {
 	struct short_channel_id *scid = tal(gossip, struct short_channel_id);
 
-	if (!fromwire_gossip_get_txout(msg, NULL, scid))
+	if (!fromwire_gossip_get_txout(msg, scid))
 		fatal("Gossip gave bad GOSSIP_GET_TXOUT message %s",
 		      tal_hex(msg, msg));
 
@@ -165,7 +165,7 @@ void gossip_init(struct lightningd *ld)
 		fatal("Could not write to HSM: %s", strerror(errno));
 
 	msg = hsm_sync_read(tmpctx, ld);
-	if (!fromwire_hsm_client_hsmfd_reply(msg, NULL))
+	if (!fromwire_hsm_client_hsmfd_reply(msg))
 		fatal("Malformed hsmfd response: %s", tal_hex(msg, msg));
 
 	hsmfd = fdpass_recv(ld->hsm_fd);
@@ -196,7 +196,7 @@ static void json_getnodes_reply(struct subd *gossip, const u8 *reply,
 	struct json_result *response = new_json_result(cmd);
 	size_t i, j;
 
-	if (!fromwire_gossip_getnodes_reply(reply, reply, NULL, &nodes)) {
+	if (!fromwire_gossip_getnodes_reply(reply, reply, &nodes)) {
 		command_fail(cmd, "Malformed gossip_getnodes response");
 		return;
 	}
@@ -270,7 +270,7 @@ static void json_getroute_reply(struct subd *gossip, const u8 *reply, const int
 	struct route_hop *hops;
 	size_t i;
 
-	fromwire_gossip_getroute_reply(reply, reply, NULL, &hops);
+	fromwire_gossip_getroute_reply(reply, reply, &hops);
 
 	if (tal_count(hops) == 0) {
 		command_fail(cmd, "Could not find a route");
@@ -362,7 +362,7 @@ static void json_listchannels_reply(struct subd *gossip, const u8 *reply,
 	struct gossip_getchannels_entry *entries;
 	struct json_result *response = new_json_result(cmd);
 
-	if (!fromwire_gossip_getchannels_reply(reply, reply, NULL, &entries)) {
+	if (!fromwire_gossip_getchannels_reply(reply, reply, &entries)) {
 		command_fail(cmd, "Invalid reply from gossipd");
 		return;
 	}
diff --git a/lightningd/hsm_control.c b/lightningd/hsm_control.c
index b76454e97..d31963393 100644
--- a/lightningd/hsm_control.c
+++ b/lightningd/hsm_control.c
@@ -51,7 +51,7 @@ void hsm_init(struct lightningd *ld, bool newdir)
 
 	ld->wallet->bip32_base = tal(ld->wallet, struct ext_key);
 	msg = hsm_sync_read(tmpctx, ld);
-	if (!fromwire_hsm_init_reply(msg, NULL,
+	if (!fromwire_hsm_init_reply(msg,
 					&ld->id,
 					&ld->peer_seed,
 					ld->wallet->bip32_base))
diff --git a/lightningd/invoice.c b/lightningd/invoice.c
index 2fd5d170f..26eb33583 100644
--- a/lightningd/invoice.c
+++ b/lightningd/invoice.c
@@ -91,7 +91,7 @@ static bool hsm_sign_b11(const u5 *u5bytes,
 		fatal("Could not write to HSM: %s", strerror(errno));
 
 	msg = hsm_sync_read(ld, ld);
-        if (!fromwire_hsm_sign_invoice_reply(msg, NULL, rsig))
+        if (!fromwire_hsm_sign_invoice_reply(msg, rsig))
 		fatal("HSM gave bad sign_invoice_reply %s",
 		      tal_hex(msg, msg));
 
diff --git a/lightningd/log_status.c b/lightningd/log_status.c
index b3181195c..d050ac9f9 100644
--- a/lightningd/log_status.c
+++ b/lightningd/log_status.c
@@ -7,12 +7,12 @@ bool log_status_msg(struct log *log, const u8 *msg)
 	u8 *data;
  	enum log_level level;
 
-	if (fromwire_status_log(msg, msg, NULL, &level, &entry)) {
+	if (fromwire_status_log(msg, msg, &level, &entry)) {
 		if (level != LOG_IO_IN && level != LOG_IO_OUT) {
 			log_(log, level, "%s", entry);
 			return true;
 		}
-	} else if (fromwire_status_io(msg, msg, NULL, &level, &data)) {
+	} else if (fromwire_status_io(msg, msg, &level, &data)) {
 		if (level == LOG_IO_IN || level == LOG_IO_OUT) {
 			log_io(log, level, "", data, tal_len(data));
 			return true;
diff --git a/lightningd/onchain_control.c b/lightningd/onchain_control.c
index 61e308380..020544a29 100644
--- a/lightningd/onchain_control.c
+++ b/lightningd/onchain_control.c
@@ -50,7 +50,7 @@ static void handle_onchain_init_reply(struct channel *channel, const u8 *msg)
 {
 	u8 state;
 
-	if (!fromwire_onchain_init_reply(msg, NULL, &state)) {
+	if (!fromwire_onchain_init_reply(msg, &state)) {
 		channel_internal_error(channel, "Invalid onchain_init_reply");
 		return;
 	}
@@ -137,7 +137,7 @@ static void handle_onchain_broadcast_tx(struct channel *channel, const u8 *msg)
 {
 	struct bitcoin_tx *tx;
 
-	if (!fromwire_onchain_broadcast_tx(msg, msg, NULL, &tx)) {
+	if (!fromwire_onchain_broadcast_tx(msg, msg, &tx)) {
 		channel_internal_error(channel, "Invalid onchain_broadcast_tx");
 		return;
 	}
@@ -151,7 +151,7 @@ static void handle_onchain_unwatch_tx(struct channel *channel, const u8 *msg)
 	struct bitcoin_txid txid;
 	struct txwatch *txw;
 
-	if (!fromwire_onchain_unwatch_tx(msg, NULL, &txid)) {
+	if (!fromwire_onchain_unwatch_tx(msg, &txid)) {
 		channel_internal_error(channel, "Invalid onchain_unwatch_tx");
 		return;
 	}
@@ -168,7 +168,7 @@ static void handle_extracted_preimage(struct channel *channel, const u8 *msg)
 {
 	struct preimage preimage;
 
-	if (!fromwire_onchain_extracted_preimage(msg, NULL, &preimage)) {
+	if (!fromwire_onchain_extracted_preimage(msg, &preimage)) {
 		channel_internal_error(channel, "Invalid extracted_preimage");
 		return;
 	}
@@ -180,7 +180,7 @@ static void handle_missing_htlc_output(struct channel *channel, const u8 *msg)
 {
 	struct htlc_stub htlc;
 
-	if (!fromwire_onchain_missing_htlc_output(msg, NULL, &htlc)) {
+	if (!fromwire_onchain_missing_htlc_output(msg, &htlc)) {
 		channel_internal_error(channel, "Invalid missing_htlc_output");
 		return;
 	}
@@ -200,7 +200,7 @@ static void handle_onchain_htlc_timeout(struct channel *channel, const u8 *msg)
 {
 	struct htlc_stub htlc;
 
-	if (!fromwire_onchain_htlc_timeout(msg, NULL, &htlc)) {
+	if (!fromwire_onchain_htlc_timeout(msg, &htlc)) {
 		channel_internal_error(channel, "Invalid onchain_htlc_timeout");
 		return;
 	}
@@ -240,7 +240,7 @@ static void onchain_add_utxo(struct channel *channel, const u8 *msg)
 	u->close_info->channel_id = channel->dbid;
 	u->close_info->peer_id = channel->peer->id;
 
-	if (!fromwire_onchain_add_utxo(msg, NULL, &u->txid, &u->outnum,
+	if (!fromwire_onchain_add_utxo(msg, &u->txid, &u->outnum,
 				       &u->close_info->commitment_point,
 				       &u->amount)) {
 		fatal("onchaind gave invalid add_utxo message: %s", tal_hex(msg, msg));
diff --git a/lightningd/opening_control.c b/lightningd/opening_control.c
index 34bf5bf03..8a574db94 100644
--- a/lightningd/opening_control.c
+++ b/lightningd/opening_control.c
@@ -234,7 +234,7 @@ static void opening_funder_finished(struct subd *openingd, const u8 *resp,
 	/* This is a new channel_info.their_config so set its ID to 0 */
 	channel_info.their_config.id = 0;
 
-	if (!fromwire_opening_funder_reply(resp, resp, NULL,
+	if (!fromwire_opening_funder_reply(resp, resp,
 					   &channel_info.their_config,
 					   &remote_commit,
 					   &remote_commit_sig,
@@ -340,7 +340,7 @@ static void opening_funder_finished(struct subd *openingd, const u8 *resp,
 		fatal("Could not write to HSM: %s", strerror(errno));
 
 	msg = hsm_sync_read(fc, ld);
-	if (!fromwire_hsm_sign_funding_reply(tmpctx, msg, NULL, &fundingtx))
+	if (!fromwire_hsm_sign_funding_reply(tmpctx, msg, &fundingtx))
 		fatal("HSM gave bad sign_funding_reply %s",
 		      tal_hex(msg, resp));
 
@@ -405,7 +405,7 @@ static void opening_fundee_finished(struct subd *openingd,
 	/* This is a new channel_info.their_config, set its ID to 0 */
 	channel_info.their_config.id = 0;
 
-	if (!fromwire_opening_fundee_reply(tmpctx, reply, NULL,
+	if (!fromwire_opening_fundee_reply(tmpctx, reply,
 					   &channel_info.their_config,
 					   &remote_commit,
 					   &remote_commit_sig,
@@ -743,10 +743,10 @@ static void gossip_peer_released(struct subd *gossip,
 
 	c = active_channel_by_id(ld, &fc->peerid, &uc);
 
-	if (!fromwire_gossipctl_release_peer_reply(fc, resp, NULL, &addr, &cs,
+	if (!fromwire_gossipctl_release_peer_reply(fc, resp, &addr, &cs,
 						   &gossip_index,
 						   &gfeatures, &lfeatures)) {
-		if (!fromwire_gossipctl_release_peer_replyfail(resp, NULL)) {
+		if (!fromwire_gossipctl_release_peer_replyfail(resp)) {
 			fatal("Gossip daemon gave invalid reply %s",
 			      tal_hex(gossip, resp));
 		}
diff --git a/lightningd/pay.c b/lightningd/pay.c
index 32c1deb29..d88ded0e9 100644
--- a/lightningd/pay.c
+++ b/lightningd/pay.c
@@ -173,19 +173,19 @@ static u8 *channel_update_from_onion_error(const tal_t *ctx,
 	 * TODO > BOLT 1.0: Add new failcodes when updating to a
 	 * new BOLT version. */
 	if (!fromwire_temporary_channel_failure(ctx,
-						onion_message, NULL,
+						onion_message,
 						&channel_update) &&
 	    !fromwire_amount_below_minimum(ctx,
-					   onion_message, NULL, &unused64,
+					   onion_message, &unused64,
 					   &channel_update) &&
 	    !fromwire_fee_insufficient(ctx,
-		    		       onion_message, NULL, &unused64,
+		    		       onion_message, &unused64,
 				       &channel_update) &&
 	    !fromwire_incorrect_cltv_expiry(ctx,
-		    			    onion_message, NULL, &unused32,
+		    			    onion_message, &unused32,
 					    &channel_update) &&
 	    !fromwire_expiry_too_soon(ctx,
-		    		      onion_message, NULL,
+		    		      onion_message,
 				      &channel_update))
 		/* No channel update. */
 		channel_update = NULL;
diff --git a/lightningd/payalgo.c b/lightningd/payalgo.c
index 9921ec9a4..19e0ccaff 100644
--- a/lightningd/payalgo.c
+++ b/lightningd/payalgo.c
@@ -149,7 +149,7 @@ static void json_pay_getroute_reply(struct subd *gossip,
 	double feepercent;
 	struct json_result *data;
 
-	fromwire_gossip_getroute_reply(reply, reply, NULL, &route);
+	fromwire_gossip_getroute_reply(reply, reply, &route);
 
 	if (tal_count(route) == 0) {
 		command_fail_detailed(pay->cmd, PAY_ROUTE_NOT_FOUND, NULL,
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index c969489ad..9753a8786 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -288,7 +288,7 @@ void peer_connected(struct lightningd *ld, const u8 *msg,
 	u64 gossip_index;
 	struct uncommitted_channel *uc;
 
-	if (!fromwire_gossip_peer_connected(msg, msg, NULL,
+	if (!fromwire_gossip_peer_connected(msg, msg,
 					    &id, &addr, &cs, &gossip_index,
 					    &gfeatures, &lfeatures))
 		fatal("Gossip gave bad GOSSIP_PEER_CONNECTED message %s",
@@ -593,7 +593,7 @@ static void gossipd_getpeers_complete(struct subd *gossip, const u8 *msg,
 	struct json_result *response = new_json_result(gpa->cmd);
 	struct peer *p;
 
-	if (!fromwire_gossip_getpeers_reply(msg, msg, NULL, &ids, &addrs)) {
+	if (!fromwire_gossip_getpeers_reply(msg, msg, &ids, &addrs)) {
 		command_fail(gpa->cmd, "Bad response from gossipd");
 		return;
 	}
diff --git a/lightningd/peer_htlcs.c b/lightningd/peer_htlcs.c
index 71c925010..fe8ef2196 100644
--- a/lightningd/peer_htlcs.c
+++ b/lightningd/peer_htlcs.c
@@ -333,7 +333,7 @@ static void rcvd_htlc_reply(struct subd *subd, const u8 *msg, const int *fds,
 	u8 *failurestr;
 	struct lightningd *ld = subd->ld;
 
-	if (!fromwire_channel_offer_htlc_reply(msg, msg, NULL,
+	if (!fromwire_channel_offer_htlc_reply(msg, msg,
 					       &hout->key.id,
 					       &failure_code,
 					       &failurestr)) {
@@ -515,7 +515,7 @@ static void channel_resolve_reply(struct subd *gossip, const u8 *msg,
 {
 	struct pubkey *nodes, *peer_id;
 
-	if (!fromwire_gossip_resolve_channel_reply(msg, msg, NULL, &nodes)) {
+	if (!fromwire_gossip_resolve_channel_reply(msg, msg, &nodes)) {
 		log_broken(gossip->log,
 			   "bad fromwire_gossip_resolve_channel_reply %s",
 			   tal_hex(msg, msg));
@@ -966,7 +966,7 @@ void peer_sending_commitsig(struct channel *channel, const u8 *msg)
 	secp256k1_ecdsa_signature *htlc_sigs;
 	struct lightningd *ld = channel->peer->ld;
 
-	if (!fromwire_channel_sending_commitsig(msg, msg, NULL,
+	if (!fromwire_channel_sending_commitsig(msg, msg,
 						&commitnum,
 						&feerate,
 						&changed_htlcs,
@@ -1112,7 +1112,7 @@ void peer_got_commitsig(struct channel *channel, const u8 *msg)
 	size_t i;
 	struct lightningd *ld = channel->peer->ld;
 
-	if (!fromwire_channel_got_commitsig(msg, msg, NULL,
+	if (!fromwire_channel_got_commitsig(msg, msg,
 					    &commitnum,
 					    &feerate,
 					    &commit_sig,
@@ -1204,7 +1204,7 @@ void peer_got_revoke(struct channel *channel, const u8 *msg)
 	size_t i;
 	struct lightningd *ld = channel->peer->ld;
 
-	if (!fromwire_channel_got_revoke(msg, msg, NULL,
+	if (!fromwire_channel_got_revoke(msg, msg,
 					 &revokenum, &per_commitment_secret,
 					 &next_per_commitment_point,
 					 &changed)) {
diff --git a/lightningd/subd.c b/lightningd/subd.c
index ab2a4ea31..a279926ef 100644
--- a/lightningd/subd.c
+++ b/lightningd/subd.c
@@ -362,7 +362,7 @@ static bool log_status_fail(struct subd *sd, const u8 *msg)
 	enum status_failreason failreason;
 	char *desc;
 
-	if (!fromwire_status_fail(msg, msg, NULL, &failreason, &desc))
+	if (!fromwire_status_fail(msg, msg, &failreason, &desc))
 		return false;
 
 	/* No 'default:' here so gcc gives warning if a new type added */
@@ -401,7 +401,7 @@ static bool handle_peer_error(struct subd *sd, const u8 *msg, int fds[2])
 	u64 gossip_index;
 	u8 *err_for_them;
 
-	if (!fromwire_status_peer_error(msg, msg, NULL,
+	if (!fromwire_status_peer_error(msg, msg,
 					&channel_id, &desc,
 					&cs, &gossip_index, &err_for_them))
 		return false;
diff --git a/onchaind/onchain.c b/onchaind/onchain.c
index 3cd6fad2a..e67a10538 100644
--- a/onchaind/onchain.c
+++ b/onchaind/onchain.c
@@ -950,12 +950,12 @@ static void wait_for_resolved(struct tracked_output **outs)
 		status_trace("Got new message %s",
 			     onchain_wire_type_name(fromwire_peektype(msg)));
 
-		if (fromwire_onchain_depth(msg, NULL, &txid, &depth))
+		if (fromwire_onchain_depth(msg, &txid, &depth))
 			tx_new_depth(outs, &txid, depth);
-		else if (fromwire_onchain_spent(msg, msg, NULL, &tx, &input_num,
+		else if (fromwire_onchain_spent(msg, msg, &tx, &input_num,
 						&tx_blockheight))
 			output_spent(&outs, tx, input_num, tx_blockheight);
-		else if (fromwire_onchain_known_preimage(msg, NULL, &preimage))
+		else if (fromwire_onchain_known_preimage(msg, &preimage))
 			handle_preimage(outs, &preimage);
 		else
 			master_badmsg(-1, msg);
@@ -1982,7 +1982,7 @@ int main(int argc, char *argv[])
 	missing_htlc_msgs = tal_arr(ctx, u8 *, 0);
 
 	msg = wire_sync_read(ctx, REQ_FD);
-	if (!fromwire_onchain_init(ctx, msg, NULL,
+	if (!fromwire_onchain_init(ctx, msg,
 				   &seed, &shachain,
 				   &funding_amount_satoshi,
 				   &old_remote_per_commit_point,
@@ -2021,7 +2021,7 @@ int main(int argc, char *argv[])
 
 	for (u64 i = 0; i < num_htlcs; i++) {
 		msg = wire_sync_read(ctx, REQ_FD);
-		if (!fromwire_onchain_htlc(msg, NULL, &htlcs[i],
+		if (!fromwire_onchain_htlc(msg, &htlcs[i],
 					   &tell_if_missing[i],
 					   &tell_immediately[i]))
 			master_badmsg(WIRE_ONCHAIN_HTLC, msg);
diff --git a/openingd/opening.c b/openingd/opening.c
index 4f06c03b0..1addc04bb 100644
--- a/openingd/opening.c
+++ b/openingd/opening.c
@@ -270,7 +270,7 @@ static u8 *funder_channel(struct state *state,
 	 * `delayed_payment_basepoint` are not valid DER-encoded compressed
 	 * secp256k1 pubkeys.
 	 */
-	if (!fromwire_accept_channel(msg, NULL, &id_in,
+	if (!fromwire_accept_channel(msg, &id_in,
 				     &state->remoteconf->dust_limit_satoshis,
 				     &state->remoteconf
 				     ->max_htlc_value_in_flight_msat,
@@ -386,7 +386,7 @@ static u8 *funder_channel(struct state *state,
 	 */
 	msg = opening_read_peer_msg(state);
 
-	if (!fromwire_funding_signed(msg, NULL, &id_in, &sig))
+	if (!fromwire_funding_signed(msg, &id_in, &sig))
 		peer_failed(&state->cs, state->gossip_index,
 			    &state->channel_id,
 			    "Parsing funding_signed: %s", tal_hex(msg, msg));
@@ -475,7 +475,7 @@ static u8 *fundee_channel(struct state *state,
 	 * `delayed_payment_basepoint` are not valid DER-encoded compressed
 	 * secp256k1 pubkeys.
 	 */
-	if (!fromwire_open_channel(peer_msg, NULL, &chain_hash,
+	if (!fromwire_open_channel(peer_msg, &chain_hash,
 				   &state->channel_id,
 				   &state->funding_satoshis, &state->push_msat,
 				   &state->remoteconf->dust_limit_satoshis,
@@ -572,7 +572,7 @@ static u8 *fundee_channel(struct state *state,
 
 	msg = opening_read_peer_msg(state);
 
-	if (!fromwire_funding_created(msg, NULL, &id_in,
+	if (!fromwire_funding_created(msg, &id_in,
 				      &state->funding_txid,
 				      &state->funding_txout,
 				      &theirsig))
@@ -699,7 +699,7 @@ int main(int argc, char *argv[])
 	status_setup_sync(REQ_FD);
 
 	msg = wire_sync_read(state, REQ_FD);
-	if (!fromwire_opening_init(msg, NULL,
+	if (!fromwire_opening_init(msg,
 				   &network_index,
 				   &state->localconf,
 				   &state->max_to_self_delay,
@@ -732,7 +732,7 @@ int main(int argc, char *argv[])
 		     type_to_string(trc, struct pubkey,
 				    &state->next_per_commit[LOCAL]));
 	msg = wire_sync_read(state, REQ_FD);
-	if (fromwire_opening_funder(state, msg, NULL,
+	if (fromwire_opening_funder(state, msg,
 				    &state->funding_satoshis,
 				    &state->push_msat,
 				    &state->feerate_per_kw, &max_minimum_depth,
@@ -742,7 +742,7 @@ int main(int argc, char *argv[])
 				     max_minimum_depth, change_satoshis,
 				     change_keyindex, channel_flags,
 				     utxos, &bip32_base);
-	else if (fromwire_opening_fundee(state, msg, NULL, &minimum_depth,
+	else if (fromwire_opening_fundee(state, msg, &minimum_depth,
 					 &min_feerate, &max_feerate, &peer_msg))
 		msg = fundee_channel(state, &our_funding_pubkey, &our_points,
 				   minimum_depth, min_feerate, max_feerate,
diff --git a/tools/generate-wire.py b/tools/generate-wire.py
index 0900b81e0..96d13e745 100755
--- a/tools/generate-wire.py
+++ b/tools/generate-wire.py
@@ -187,24 +187,20 @@ class Field(object):
 
         raise ValueError('Unknown size {} for {}'.format(base_size,fieldname))
 
-fromwire_impl_templ = """bool fromwire_{name}({ctx}const void *p, size_t *plen{args})
+fromwire_impl_templ = """bool fromwire_{name}({ctx}const void *p{args})
 {{
 {fields}
 	const u8 *cursor = p;
-	size_t tmp_len;
+	size_t plen = tal_len(p);
 
-	if (!plen) {{
-		tmp_len = tal_count(p);
-		plen = &tmp_len;
-	}}
-	if (fromwire_u16(&cursor, plen) != {enum.name})
+	if (fromwire_u16(&cursor, &plen) != {enum.name})
 		return false;
 {subcalls}
 	return cursor != NULL;
 }}
 """
 
-fromwire_header_templ = """bool fromwire_{name}({ctx}const void *p, size_t *plen{args});
+fromwire_header_templ = """bool fromwire_{name}({ctx}const void *p{args});
 """
 
 towire_header_templ = """u8 *towire_{name}(const tal_t *ctx{args});
@@ -274,19 +270,19 @@ class Message(object):
 
     def print_fromwire_array(self, subcalls, basetype, f, name, num_elems):
         if f.has_array_helper():
-            subcalls.append('\tfromwire_{}_array(&cursor, plen, {}, {});'
+            subcalls.append('\tfromwire_{}_array(&cursor, &plen, {}, {});'
                             .format(basetype, name, num_elems))
         else:
             subcalls.append('\tfor (size_t i = 0; i < {}; i++)'
                             .format(num_elems))
             if f.fieldtype.is_assignable():
-                subcalls.append('\t\t({})[i] = fromwire_{}(&cursor, plen);'
+                subcalls.append('\t\t({})[i] = fromwire_{}(&cursor, &plen);'
                                 .format(name, basetype))
             elif basetype in varlen_structs:
-                subcalls.append('\t\t({})[i] = fromwire_{}(ctx, &cursor, plen);'
+                subcalls.append('\t\t({})[i] = fromwire_{}(ctx, &cursor, &plen);'
                                 .format(name, basetype))
             else:
-                subcalls.append('\t\tfromwire_{}(&cursor, plen, {} + i);'
+                subcalls.append('\t\tfromwire_{}(&cursor, &plen, {} + i);'
                                 .format(basetype, name))
 
     def print_fromwire(self,is_header):
@@ -321,7 +317,7 @@ class Message(object):
                 subcalls.append('\t/*{} */'.format(c))
 
             if f.is_padding():
-                subcalls.append('\tfromwire_pad(&cursor, plen, {});'
+                subcalls.append('\tfromwire_pad(&cursor, &plen, {});'
                                 .format(f.num_elems))
             elif f.is_array():
                 self.print_fromwire_array(subcalls, basetype, f, f.name,
@@ -340,16 +336,16 @@ class Message(object):
             elif f.is_assignable():
                 subcalls.append("\t//3th case {name}".format(name=f.name))
                 if f.is_len_var:
-                    subcalls.append('\t{} = fromwire_{}(&cursor, plen);'
+                    subcalls.append('\t{} = fromwire_{}(&cursor, &plen);'
                                     .format(f.name, basetype))
                 else:
-                    subcalls.append('\t*{} = fromwire_{}(&cursor, plen);'
+                    subcalls.append('\t*{} = fromwire_{}(&cursor, &plen);'
                                     .format(f.name, basetype))
             elif basetype in varlen_structs:
-                subcalls.append('\t*{} = fromwire_{}(ctx, &cursor, plen);'
+                subcalls.append('\t*{} = fromwire_{}(ctx, &cursor, &plen);'
                                 .format(f.name, basetype))
             else:
-                subcalls.append('\tfromwire_{}(&cursor, plen, {});'
+                subcalls.append('\tfromwire_{}(&cursor, &plen, {});'
                                 .format(basetype, f.name))
 
         return template.format(
diff --git a/wallet/test/run-wallet.c b/wallet/test/run-wallet.c
index 856a62633..b28a2131e 100644
--- a/wallet/test/run-wallet.c
+++ b/wallet/test/run-wallet.c
@@ -74,10 +74,10 @@ bool derive_basepoints(const struct privkey *seed UNNEEDED,
 bool extract_channel_id(const u8 *in_pkt UNNEEDED, struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "extract_channel_id called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_getpeers_reply */
-bool fromwire_gossip_getpeers_reply(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, struct pubkey **id UNNEEDED, struct wireaddr **addr UNNEEDED)
+bool fromwire_gossip_getpeers_reply(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct pubkey **id UNNEEDED, struct wireaddr **addr UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_getpeers_reply called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_peer_connected */
-bool fromwire_gossip_peer_connected(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, struct pubkey *id UNNEEDED, struct wireaddr *addr UNNEEDED, struct crypto_state *crypto_state UNNEEDED, u64 *gossip_index UNNEEDED, u8 **gfeatures UNNEEDED, u8 **lfeatures UNNEEDED)
+bool fromwire_gossip_peer_connected(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct pubkey *id UNNEEDED, struct wireaddr *addr UNNEEDED, struct crypto_state *crypto_state UNNEEDED, u64 *gossip_index UNNEEDED, u8 **gfeatures UNNEEDED, u8 **lfeatures UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_peer_connected called!\n"); abort(); }
 /* Generated stub for funding_spent */
 enum watch_result funding_spent(struct channel *channel UNNEEDED,
diff --git a/wallet/walletrpc.c b/wallet/walletrpc.c
index 27a7eb4b0..92267954d 100644
--- a/wallet/walletrpc.c
+++ b/wallet/walletrpc.c
@@ -290,7 +290,7 @@ static void json_withdraw(struct command *cmd,
 
 	msg = hsm_sync_read(cmd, cmd->ld);
 
-	if (!fromwire_hsm_sign_withdrawal_reply(msg, msg, NULL, &tx))
+	if (!fromwire_hsm_sign_withdrawal_reply(msg, msg, &tx))
 		fatal("HSM gave bad sign_withdrawal_reply %s",
 		      tal_hex(withdraw, msg));
 
diff --git a/wire/peer_wire.c b/wire/peer_wire.c
index ff1ac56cf..9e2f30eae 100644
--- a/wire/peer_wire.c
+++ b/wire/peer_wire.c
@@ -84,10 +84,10 @@ bool extract_channel_id(const u8 *in_pkt, struct channel_id *channel_id)
 	struct pubkey ignored_pubkey;
 	struct bitcoin_blkid ignored_chainhash;
 
-	if (fromwire_channel_reestablish(in_pkt, NULL, channel_id,
+	if (fromwire_channel_reestablish(in_pkt, channel_id,
 					 &ignored_u64, &ignored_u64))
 		return true;
-	if (fromwire_open_channel(in_pkt, NULL, &ignored_chainhash,
+	if (fromwire_open_channel(in_pkt, &ignored_chainhash,
 				  channel_id, &ignored_u64,
 				  &ignored_u64, &ignored_u64,
 				  &ignored_u64, &ignored_u64,
diff --git a/wire/test/run-peer-wire.c b/wire/test/run-peer-wire.c
index f926160b2..3ed3531bc 100644
--- a/wire/test/run-peer-wire.c
+++ b/wire/test/run-peer-wire.c
@@ -228,10 +228,10 @@ static void *towire_struct_channel_announcement(const tal_t *ctx,
 					   &s->bitcoin_key_2);
 }
 
-static struct msg_channel_announcement *fromwire_struct_channel_announcement(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_channel_announcement *fromwire_struct_channel_announcement(const tal_t *ctx, const void *p)
 {
 	struct msg_channel_announcement *s = tal(ctx, struct msg_channel_announcement);
-	if (!fromwire_channel_announcement(s, p, plen,
+	if (!fromwire_channel_announcement(s, p,
 					  &s->node_signature_1,
 					  &s->node_signature_2,
 					  &s->bitcoin_signature_1,
@@ -271,11 +271,11 @@ static void *towire_struct_open_channel(const tal_t *ctx,
 				   s->channel_flags);
 }
 
-static struct msg_open_channel *fromwire_struct_open_channel(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_open_channel *fromwire_struct_open_channel(const tal_t *ctx, const void *p)
 {
 	struct msg_open_channel *s = tal(ctx, struct msg_open_channel);
 
-	if (fromwire_open_channel(p, plen,
+	if (fromwire_open_channel(p,
 				  &s->chain_hash,
 				  &s->temporary_channel_id,
 				  &s->funding_satoshis,
@@ -318,11 +318,11 @@ static void *towire_struct_accept_channel(const tal_t *ctx,
 				     &s->first_per_commitment_point);
 }
 
-static struct msg_accept_channel *fromwire_struct_accept_channel(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_accept_channel *fromwire_struct_accept_channel(const tal_t *ctx, const void *p)
 {
 	struct msg_accept_channel *s = tal(ctx, struct msg_accept_channel);
 
-	if (fromwire_accept_channel(p, plen,
+	if (fromwire_accept_channel(p,
 				    &s->temporary_channel_id,
 				    &s->dust_limit_satoshis,
 				    &s->max_htlc_value_in_flight_msat,
@@ -354,10 +354,10 @@ static void *towire_struct_node_announcement(const tal_t *ctx,
 					s->addresses);
 }
 
-static struct msg_node_announcement *fromwire_struct_node_announcement(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_node_announcement *fromwire_struct_node_announcement(const tal_t *ctx, const void *p)
 {
 	struct msg_node_announcement *s = tal(ctx, struct msg_node_announcement);
-	if (!fromwire_node_announcement(s, p, plen,
+	if (!fromwire_node_announcement(s, p,
 				       &s->signature,
 					&s->features,
 				       &s->timestamp,
@@ -384,11 +384,11 @@ static void *towire_struct_channel_update(const tal_t *ctx,
 				     s->fee_proportional_millionths);
 }
 
-static struct msg_channel_update *fromwire_struct_channel_update(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_channel_update *fromwire_struct_channel_update(const tal_t *ctx, const void *p)
 {
 	struct msg_channel_update *s = tal(ctx, struct msg_channel_update);
 
-	if (fromwire_channel_update(p, plen,
+	if (fromwire_channel_update(p,
 				    &s->signature,
 				    &s->chain_hash,
 				    &s->short_channel_id,
@@ -410,11 +410,11 @@ static void *towire_struct_funding_locked(const tal_t *ctx,
 				     &s->next_per_commitment_point);
 }
 
-static struct msg_funding_locked *fromwire_struct_funding_locked(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_funding_locked *fromwire_struct_funding_locked(const tal_t *ctx, const void *p)
 {
 	struct msg_funding_locked *s = tal(ctx, struct msg_funding_locked);
 
-	if (fromwire_funding_locked(p, plen,
+	if (fromwire_funding_locked(p,
 				    &s->channel_id,
 				    &s->next_per_commitment_point))
 		return s;
@@ -431,11 +431,11 @@ static void *towire_struct_announcement_signatures(const tal_t *ctx,
 				     &s->announcement_bitcoin_signature);
 }
 
-static struct msg_announcement_signatures *fromwire_struct_announcement_signatures(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_announcement_signatures *fromwire_struct_announcement_signatures(const tal_t *ctx, const void *p)
 {
 	struct msg_announcement_signatures *s = tal(ctx, struct msg_announcement_signatures);
 
-	if (fromwire_announcement_signatures(p, plen,
+	if (fromwire_announcement_signatures(p,
 				    &s->channel_id,
 				    &s->short_channel_id,
 				    &s->announcement_node_signature,
@@ -453,11 +453,11 @@ static void *towire_struct_update_fail_htlc(const tal_t *ctx,
 				       s->reason);
 }
 
-static struct msg_update_fail_htlc *fromwire_struct_update_fail_htlc(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_update_fail_htlc *fromwire_struct_update_fail_htlc(const tal_t *ctx, const void *p)
 {
 	struct msg_update_fail_htlc *s = tal(ctx, struct msg_update_fail_htlc);
 
-	if (!fromwire_update_fail_htlc(ctx, p, plen,
+	if (!fromwire_update_fail_htlc(ctx, p,
 				      &s->channel_id,
 				      &s->id,
 				      &s->reason))
@@ -475,11 +475,11 @@ static void *towire_struct_update_fulfill_htlc(const tal_t *ctx,
 				       &s->payment_preimage);
 }
 
-static struct msg_update_fulfill_htlc *fromwire_struct_update_fulfill_htlc(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_update_fulfill_htlc *fromwire_struct_update_fulfill_htlc(const tal_t *ctx, const void *p)
 {
 	struct msg_update_fulfill_htlc *s = tal(ctx, struct msg_update_fulfill_htlc);
 
-	if (fromwire_update_fulfill_htlc(p, plen,
+	if (fromwire_update_fulfill_htlc(p,
 				      &s->channel_id,
 				      &s->id,
 				      &s->payment_preimage))
@@ -496,11 +496,11 @@ static void *towire_struct_commitment_signed(const tal_t *ctx,
 					s->htlc_signature);
 }
 
-static struct msg_commitment_signed *fromwire_struct_commitment_signed(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_commitment_signed *fromwire_struct_commitment_signed(const tal_t *ctx, const void *p)
 {
 	struct msg_commitment_signed *s = tal(ctx, struct msg_commitment_signed);
 
-	if (!fromwire_commitment_signed(s, p, plen,
+	if (!fromwire_commitment_signed(s, p,
 				&s->channel_id,
 				&s->signature,
 				&s->htlc_signature))
@@ -517,11 +517,11 @@ static void *towire_struct_revoke_and_ack(const tal_t *ctx,
 				     &s->next_per_commitment_point);
 }
 
-static struct msg_revoke_and_ack *fromwire_struct_revoke_and_ack(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_revoke_and_ack *fromwire_struct_revoke_and_ack(const tal_t *ctx, const void *p)
 {
 	struct msg_revoke_and_ack *s = tal(ctx, struct msg_revoke_and_ack);
 
-	if (!fromwire_revoke_and_ack(p, plen,
+	if (!fromwire_revoke_and_ack(p,
 				     &s->channel_id,
 				     &s->per_commitment_secret,
 				     &s->next_per_commitment_point))
@@ -538,11 +538,11 @@ static void *towire_struct_funding_signed(const tal_t *ctx,
 				     &s->signature);
 }
 
-static struct msg_funding_signed *fromwire_struct_funding_signed(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_funding_signed *fromwire_struct_funding_signed(const tal_t *ctx, const void *p)
 {
 	struct msg_funding_signed *s = tal(ctx, struct msg_funding_signed);
 
-	if (fromwire_funding_signed(p, plen,
+	if (fromwire_funding_signed(p,
 				    &s->temporary_channel_id,
 				    &s->signature))
 		return s;
@@ -558,11 +558,11 @@ static void *towire_struct_closing_signed(const tal_t *ctx,
 				     &s->signature);
 }
 
-static struct msg_closing_signed *fromwire_struct_closing_signed(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_closing_signed *fromwire_struct_closing_signed(const tal_t *ctx, const void *p)
 {
 	struct msg_closing_signed *s = tal(ctx, struct msg_closing_signed);
 
-	if (fromwire_closing_signed(p, plen,
+	if (fromwire_closing_signed(p,
 				    &s->channel_id,
 				    &s->fee_satoshis,
 				    &s->signature))
@@ -578,11 +578,11 @@ static void *towire_struct_shutdown(const tal_t *ctx,
 			       s->scriptpubkey);
 }
 
-static struct msg_shutdown *fromwire_struct_shutdown(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_shutdown *fromwire_struct_shutdown(const tal_t *ctx, const void *p)
 {
 	struct msg_shutdown *s = tal(ctx, struct msg_shutdown);
 
-	if (!fromwire_shutdown(s, p, plen,
+	if (!fromwire_shutdown(s, p,
 			      &s->channel_id,
 			      &s->scriptpubkey))
 		return tal_free(s);
@@ -599,11 +599,11 @@ static void *towire_struct_funding_created(const tal_t *ctx,
 				      &s->signature);
 }
 
-static struct msg_funding_created *fromwire_struct_funding_created(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_funding_created *fromwire_struct_funding_created(const tal_t *ctx, const void *p)
 {
 	struct msg_funding_created *s = tal(ctx, struct msg_funding_created);
 
-	if (fromwire_funding_created(p, plen,
+	if (fromwire_funding_created(p,
 				     &s->temporary_channel_id,
 				     &s->txid,
 				     &s->output_index,
@@ -620,11 +620,11 @@ static void *towire_struct_error(const tal_t *ctx,
 			    s->data);
 }
 
-static struct msg_error *fromwire_struct_error(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_error *fromwire_struct_error(const tal_t *ctx, const void *p)
 {
 	struct msg_error *s = tal(ctx, struct msg_error);
 
-	if (!fromwire_error(s, p, plen,
+	if (!fromwire_error(s, p,
 			   &s->channel_id,
 			    &s->data))
 		return tal_free(s);
@@ -643,11 +643,11 @@ static void *towire_struct_update_add_htlc(const tal_t *ctx,
 				      s->onion_routing_packet);
 }
 
-static struct msg_update_add_htlc *fromwire_struct_update_add_htlc(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_update_add_htlc *fromwire_struct_update_add_htlc(const tal_t *ctx, const void *p)
 {
 	struct msg_update_add_htlc *s = tal(ctx, struct msg_update_add_htlc);
 
-	if (fromwire_update_add_htlc(p, plen,
+	if (fromwire_update_add_htlc(p,
 				     &s->channel_id,
 				     &s->id,
 				     &s->amount_msat,
@@ -667,11 +667,11 @@ static void *towire_struct_update_fee(const tal_t *ctx,
 				 s->feerate_per_kw);
 }
 
-static struct msg_update_fee *fromwire_struct_update_fee(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_update_fee *fromwire_struct_update_fee(const tal_t *ctx, const void *p)
 {
 	struct msg_update_fee *s = tal(ctx, struct msg_update_fee);
 
-	if (fromwire_update_fee(p, plen,
+	if (fromwire_update_fee(p,
 				&s->channel_id,
 				&s->feerate_per_kw))
 		return s;
@@ -686,11 +686,11 @@ static void *towire_struct_init(const tal_t *ctx,
 			   s->localfeatures);
 }
 
-static struct msg_init *fromwire_struct_init(const tal_t *ctx, const void *p, size_t *plen)
+static struct msg_init *fromwire_struct_init(const tal_t *ctx, const void *p)
 {
 	struct msg_init *s = tal(ctx, struct msg_init);
 
-	if (!fromwire_init(s, p, plen,
+	if (!fromwire_init(s, p,
 			  &s->globalfeatures,
 			  &s->localfeatures))
 		return tal_free(s);
@@ -831,15 +831,14 @@ static bool node_announcement_eq(const struct msg_node_announcement *a,
 /* Try flipping each bit, try running short. */
 #define test_corruption(a, b, type)				\
 	for (i = 0; i < tal_count(msg) * 8; i++) {		\
-		len = tal_count(msg);				\
 		msg[i / 8] ^= (1 << (i%8));			\
-		b = fromwire_struct_##type(ctx, msg, &len);	\
+		b = fromwire_struct_##type(ctx, msg);	\
 		assert(!b || !type##_eq(a, b));			\
 		msg[i / 8] ^= (1 << (i%8));			\
 	}							\
 	for (i = 0; i < tal_count(msg); i++) {			\
-		len = i;					\
-		b = fromwire_struct_##type(ctx, msg, &len);	\
+		u8 *trunc = tal_dup_arr(ctx, u8, msg, i, 0);	\
+		b = fromwire_struct_##type(ctx, trunc);		\
 		assert(!b);					\
 	}
 
@@ -865,7 +864,7 @@ int main(void)
 	struct msg_update_add_htlc uah, *uah2;
 	struct msg_node_announcement na, *na2;
 	void *ctx = tal(NULL, char);
-	size_t i, len;
+	size_t i;
 	u8 *msg;
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
@@ -880,9 +879,7 @@ int main(void)
  	memset(ca.features, 2, 2);
 
 	msg = towire_struct_channel_announcement(ctx, &ca);
-	len = tal_count(msg);
-	ca2 = fromwire_struct_channel_announcement(ctx, msg, &len);
-	assert(len == 0);
+	ca2 = fromwire_struct_channel_announcement(ctx, msg);
 	assert(channel_announcement_eq(&ca, ca2));
 	test_corruption(&ca, ca2, channel_announcement);
 
@@ -890,18 +887,14 @@ int main(void)
 	set_pubkey(&fl.next_per_commitment_point);
 
 	msg = towire_struct_funding_locked(ctx, &fl);
-	len = tal_count(msg);
-	fl2 = fromwire_struct_funding_locked(ctx, msg, &len);
-	assert(len == 0);
+	fl2 = fromwire_struct_funding_locked(ctx, msg);
 	assert(funding_locked_eq(&fl, fl2));
 	test_corruption(&fl, fl2, funding_locked);
 
 	memset(&as, 2, sizeof(as));
 
 	msg = towire_struct_announcement_signatures(ctx, &as);
-	len = tal_count(msg);
-	as2 = fromwire_struct_announcement_signatures(ctx, msg, &len);
-	assert(len == 0);
+	as2 = fromwire_struct_announcement_signatures(ctx, msg);
 	assert(announcement_signatures_eq(&as, as2));
 	test_corruption(&as, as2, announcement_signatures);
 
@@ -910,9 +903,7 @@ int main(void)
  	memset(ufh.reason, 2, 2);
 
 	msg = towire_struct_update_fail_htlc(ctx, &ufh);
-	len = tal_count(msg);
-	ufh2 = fromwire_struct_update_fail_htlc(ctx, msg, &len);
-	assert(len == 0);
+	ufh2 = fromwire_struct_update_fail_htlc(ctx, msg);
 	assert(update_fail_htlc_eq(&ufh, ufh2));
 	test_corruption(&ufh, ufh2, update_fail_htlc);
 
@@ -921,36 +912,28 @@ int main(void)
 	memset(cs.htlc_signature, 2, sizeof(secp256k1_ecdsa_signature)*2);
 
 	msg = towire_struct_commitment_signed(ctx, &cs);
-	len = tal_count(msg);
-	cs2 = fromwire_struct_commitment_signed(ctx, msg, &len);
-	assert(len == 0);
+	cs2 = fromwire_struct_commitment_signed(ctx, msg);
 	assert(commitment_signed_eq(&cs, cs2));
 	test_corruption(&cs, cs2, commitment_signed);
 
 	memset(&fs, 2, sizeof(fs));
 
 	msg = towire_struct_funding_signed(ctx, &fs);
-	len = tal_count(msg);
-	fs2 = fromwire_struct_funding_signed(ctx, msg, &len);
-	assert(len == 0);
+	fs2 = fromwire_struct_funding_signed(ctx, msg);
 	assert(funding_signed_eq(&fs, fs2));
 	test_corruption(&fs, fs2, funding_signed);
 
 	memset(&cls, 2, sizeof(cls));
 
 	msg = towire_struct_closing_signed(ctx, &cls);
-	len = tal_count(msg);
-	cls2 = fromwire_struct_closing_signed(ctx, msg, &len);
-	assert(len == 0);
+	cls2 = fromwire_struct_closing_signed(ctx, msg);
 	assert(closing_signed_eq(&cls, cls2));
 	test_corruption(&cls, cls2, closing_signed);
 
 	memset(&uflh, 2, sizeof(uflh));
 
 	msg = towire_struct_update_fulfill_htlc(ctx, &uflh);
-	len = tal_count(msg);
-	uflh2 = fromwire_struct_update_fulfill_htlc(ctx, msg, &len);
-	assert(len == 0);
+	uflh2 = fromwire_struct_update_fulfill_htlc(ctx, msg);
 	assert(update_fulfill_htlc_eq(&uflh, uflh2));
 	test_corruption(&uflh, uflh2, update_fulfill_htlc);
 
@@ -959,9 +942,7 @@ int main(void)
 	memset(e.data, 2, 2);
 
 	msg = towire_struct_error(ctx, &e);
-	len = tal_count(msg);
-	e2 = fromwire_struct_error(ctx, msg, &len);
-	assert(len == 0);
+	e2 = fromwire_struct_error(ctx, msg);
 	assert(error_eq(&e, e2));
 	test_corruption(&e, e2, error);
 
@@ -972,18 +953,14 @@ int main(void)
 	memset(init.localfeatures, 2, 2);
 
 	msg = towire_struct_init(ctx, &init);
-	len = tal_count(msg);
-	init2 = fromwire_struct_init(ctx, msg, &len);
-	assert(len == 0);
+	init2 = fromwire_struct_init(ctx, msg);
 	assert(init_eq(&init, init2));
 	test_corruption(&init, init2, init);
 
 	memset(&uf, 2, sizeof(uf));
 
 	msg = towire_struct_update_fee(ctx, &uf);
-	len = tal_count(msg);
-	uf2 = fromwire_struct_update_fee(ctx, msg, &len);
-	assert(len == 0);
+	uf2 = fromwire_struct_update_fee(ctx, msg);
 	assert(update_fee_eq(&uf, uf2));
 	test_corruption(&uf, uf2, update_fee);
 
@@ -992,18 +969,14 @@ int main(void)
 	memset(shutdown.scriptpubkey, 2, 2);
 
 	msg = towire_struct_shutdown(ctx, &shutdown);
-	len = tal_count(msg);
-	shutdown2 = fromwire_struct_shutdown(ctx, msg, &len);
-	assert(len == 0);
+	shutdown2 = fromwire_struct_shutdown(ctx, msg);
 	assert(shutdown_eq(&shutdown, shutdown2));
 	test_corruption(&shutdown, shutdown2, shutdown);
 
 	memset(&fc, 2, sizeof(fc));
 
 	msg = towire_struct_funding_created(ctx, &fc);
-	len = tal_count(msg);
-	fc2 = fromwire_struct_funding_created(ctx, msg, &len);
-	assert(len == 0);
+	fc2 = fromwire_struct_funding_created(ctx, msg);
 	assert(funding_created_eq(&fc, fc2));
 	test_corruption(&fc, fc2, funding_created);
 
@@ -1011,9 +984,7 @@ int main(void)
 	set_pubkey(&raa.next_per_commitment_point);
 
 	msg = towire_struct_revoke_and_ack(ctx, &raa);
-	len = tal_count(msg);
-	raa2 = fromwire_struct_revoke_and_ack(ctx, msg, &len);
-	assert(len == 0);
+	raa2 = fromwire_struct_revoke_and_ack(ctx, msg);
 	assert(revoke_and_ack_eq(&raa, raa2));
 	test_corruption(&raa, raa2, revoke_and_ack);
 
@@ -1026,18 +997,14 @@ int main(void)
 	set_pubkey(&oc.first_per_commitment_point);
 
 	msg = towire_struct_open_channel(ctx, &oc);
-	len = tal_count(msg);
-	oc2 = fromwire_struct_open_channel(ctx, msg, &len);
-	assert(len == 0);
+	oc2 = fromwire_struct_open_channel(ctx, msg);
 	assert(open_channel_eq(&oc, oc2));
 	test_corruption(&oc, oc2, open_channel);
 
 	memset(&cu, 2, sizeof(cu));
 
 	msg = towire_struct_channel_update(ctx, &cu);
-	len = tal_count(msg);
-	cu2 = fromwire_struct_channel_update(ctx, msg, &len);
-	assert(len == 0);
+	cu2 = fromwire_struct_channel_update(ctx, msg);
 	assert(channel_update_eq(&cu, cu2));
 	test_corruption(&cu, cu2, channel_update);
 
@@ -1050,18 +1017,14 @@ int main(void)
 	set_pubkey(&ac.first_per_commitment_point);
 
 	msg = towire_struct_accept_channel(ctx, &ac);
-	len = tal_count(msg);
-	ac2 = fromwire_struct_accept_channel(ctx, msg, &len);
-	assert(len == 0);
+	ac2 = fromwire_struct_accept_channel(ctx, msg);
 	assert(accept_channel_eq(&ac, ac2));
 	test_corruption(&ac, ac2, accept_channel);
 
 	memset(&uah, 2, sizeof(uah));
 
 	msg = towire_struct_update_add_htlc(ctx, &uah);
-	len = tal_count(msg);
-	uah2 = fromwire_struct_update_add_htlc(ctx, msg, &len);
-	assert(len == 0);
+	uah2 = fromwire_struct_update_add_htlc(ctx, msg);
 	assert(update_add_htlc_eq(&uah, uah2));
 	test_corruption(&uah, uah2, update_add_htlc);
 
@@ -1073,9 +1036,7 @@ int main(void)
 	memset(na.addresses, 2, 2);
 
 	msg = towire_struct_node_announcement(ctx, &na);
-	len = tal_count(msg);
-	na2 = fromwire_struct_node_announcement(ctx, msg, &len);
-	assert(len == 0);
+	na2 = fromwire_struct_node_announcement(ctx, msg);
 	assert(node_announcement_eq(&na, na2));
 	test_corruption(&na, na2, node_announcement);