diff --git a/lightningd/htlc_end.c b/lightningd/htlc_end.c
index c6d17709b..acf9d180e 100644
--- a/lightningd/htlc_end.c
+++ b/lightningd/htlc_end.c
@@ -150,6 +150,7 @@ struct htlc_out *new_htlc_out(const tal_t *ctx,
 	hout->dbid = 0;
 
 	hout->key.peer = peer;
+	hout->key.id = HTLC_INVALID_ID;
 	hout->msatoshi = msatoshi;
 	hout->cltv_expiry = cltv_expiry;
 	hout->payment_hash = *payment_hash;
diff --git a/lightningd/htlc_end.h b/lightningd/htlc_end.h
index 9e41375df..140300c7b 100644
--- a/lightningd/htlc_end.h
+++ b/lightningd/htlc_end.h
@@ -13,6 +13,8 @@ struct htlc_key {
 	u64 id;
 };
 
+#define HTLC_INVALID_ID (-1ULL)
+
 /* Incoming HTLC */
 struct htlc_in {
 	/* The database primary key for this htlc. Must be 0 until it
diff --git a/lightningd/peer_htlcs.c b/lightningd/peer_htlcs.c
index ab15745b2..0d98685d6 100644
--- a/lightningd/peer_htlcs.c
+++ b/lightningd/peer_htlcs.c
@@ -352,7 +352,8 @@ static void rcvd_htlc_reply(struct subd *subd, const u8 *msg, const int *fds,
 		return;
 	}
 
-	if (find_htlc_out(&subd->ld->htlcs_out, hout->key.peer, hout->key.id)) {
+	if (find_htlc_out(&subd->ld->htlcs_out, hout->key.peer, hout->key.id)
+	    || hout->key.id == HTLC_INVALID_ID) {
 		peer_internal_error(subd->peer,
 				    "Bad offer_htlc_reply HTLC id %"PRIu64
 				    " is a duplicate",