diff --git a/onchaind/onchain.c b/onchaind/onchain.c
index c40312c88..b3b039a46 100644
--- a/onchaind/onchain.c
+++ b/onchaind/onchain.c
@@ -508,7 +508,7 @@ static void unwatch_tx(const struct bitcoin_tx *tx)
 
 	bitcoin_txid(tx, &txid);
 
-	msg = towire_onchain_unwatch_tx(tx, &txid, tal_count(tx->output));
+	msg = towire_onchain_unwatch_tx(tx, &txid);
 	wire_sync_write(REQ_FD, take(msg));
 }
 
diff --git a/onchaind/onchain_wire.csv b/onchaind/onchain_wire.csv
index d30ef3fd7..7cd9d285d 100644
--- a/onchaind/onchain_wire.csv
+++ b/onchaind/onchain_wire.csv
@@ -62,7 +62,6 @@ onchain_depth,,depth,u32
 # onchaind->master: We don't want to watch this tx, or its outputs
 onchain_unwatch_tx,5006
 onchain_unwatch_tx,,txid,struct bitcoin_txid
-onchain_unwatch_tx,,num_outputs,u32
 
 # master->onchaind: We know HTLC preimage
 onchain_known_preimage,5007