diff --git a/tests/fuzz/fuzz-wire-update_add_htlc.c b/tests/fuzz/fuzz-wire-update_add_htlc.c
new file mode 100644
index 000000000..f30ae7e89
--- /dev/null
+++ b/tests/fuzz/fuzz-wire-update_add_htlc.c
@@ -0,0 +1,59 @@
+#include "config.h"
+#include <assert.h>
+#include <ccan/mem/mem.h>
+#include <stdint.h>
+#include <tests/fuzz/libfuzz.h>
+#include <tests/fuzz/wire.h>
+#include <wire/peer_wire.h>
+
+struct update_add_htlc {
+	struct channel_id channel_id;
+	u64 id;
+	struct amount_msat amount_msat;
+	struct sha256 payment_hash;
+	u32 expiry;
+	u8 onion_routing_packet[1366];
+	struct tlv_update_add_htlc_tlvs *tlvs;
+};
+
+static void *encode(const tal_t *ctx, const struct update_add_htlc *s)
+{
+	return towire_update_add_htlc(
+	    ctx, &s->channel_id, s->id, s->amount_msat, &s->payment_hash,
+	    s->expiry, s->onion_routing_packet, s->tlvs);
+}
+
+static struct update_add_htlc *decode(const tal_t *ctx, const void *p)
+{
+	struct update_add_htlc *s = tal(ctx, struct update_add_htlc);
+
+	if (fromwire_update_add_htlc(
+		s, p, &s->channel_id, &s->id, &s->amount_msat, &s->payment_hash,
+		&s->expiry, s->onion_routing_packet, &s->tlvs))
+		return s;
+	return tal_free(s);
+}
+
+static bool equal(const struct update_add_htlc *x,
+		  const struct update_add_htlc *y)
+{
+	size_t upto_expiry = (uintptr_t)&x->expiry - (uintptr_t)x;
+	if (memcmp(x, y, upto_expiry) != 0)
+		return false;
+	if (x->expiry != y->expiry)
+		return false;
+	if (memcmp(x->onion_routing_packet, y->onion_routing_packet,
+		   sizeof(x->onion_routing_packet)) != 0)
+		return false;
+
+	assert(x->tlvs && y->tlvs);
+	return memeq(
+	    x->tlvs->blinding_point, tal_bytelen(x->tlvs->blinding_point),
+	    y->tlvs->blinding_point, tal_bytelen(y->tlvs->blinding_point));
+}
+
+void run(const u8 *data, size_t size)
+{
+	test_decode_encode(data, size, WIRE_UPDATE_ADD_HTLC,
+			   struct update_add_htlc);
+}