diff --git a/Makefile b/Makefile
index 8e40d5a4d..c054b05aa 100644
--- a/Makefile
+++ b/Makefile
@@ -190,7 +190,9 @@ test-onion3: test/test_onion test/onion_key
 test-onion4: test/test_onion test/onion_key
 	set -e; TMPF=/tmp/onion.$$$$; python test/test_onion.py generate $$(test/onion_key --pub `seq 20`) > $$TMPF; for k in `seq 20`; do python test/test_onion.py decode $$(test/onion_key --priv $$k) $$(test/onion_key --pub $$k) < $$TMPF > $$TMPF.unwrap; mv $$TMPF.unwrap $$TMPF; done; rm -f $$TMPF
 
-check: daemon-tests test-onion
+check: daemon-tests test-onion bitcoin-tests
+
+include bitcoin/Makefile
 
 # Keep includes in alpha order.
 check-src-include-order/%: %
diff --git a/bitcoin/Makefile b/bitcoin/Makefile
new file mode 100644
index 000000000..b066db0a5
--- /dev/null
+++ b/bitcoin/Makefile
@@ -0,0 +1,18 @@
+# Included for one dir up.
+
+# Note that these actually #include everything they need, except ccan/.
+# That allows for unit testing of statics, and special effects.
+
+BITCOIN_TEST_SRC := $(wildcard bitcoin/test/run-*.c)
+BITCOIN_TEST_OBJS := $(BITCOIN_TEST_SRC:.c=.o)
+BITCOIN_TEST_PROGRAMS := $(BITCOIN_TEST_OBJS:.o=)
+
+$(BITCOIN_TEST_PROGRAMS): $(CCAN_OBJS)
+
+$(BITCOIN_TEST_OBJS): $(CCAN_HEADERS) $(BITCOIN_HEADERS) $(BITCOIN_SRC)
+
+VALGRIND=valgrind -q --error-exitcode=99
+VALGRIND_TEST_ARGS = --track-origins=yes --leak-check=full --show-reachable=yes
+
+bitcoin-tests: $(BITCOIN_TEST_PROGRAMS)
+	set -e; for f in $(BITCOIN_TEST_PROGRAMS); do $(VALGRIND) $(VALGRIND_TEST_ARGS) $$f; done
diff --git a/bitcoin/test/run-tx-encode.c b/bitcoin/test/run-tx-encode.c
new file mode 100644
index 000000000..dea5f735e
--- /dev/null
+++ b/bitcoin/test/run-tx-encode.c
@@ -0,0 +1,60 @@
+#include "bitcoin/tx.c"
+#include "bitcoin/shadouble.c"
+#include <assert.h>
+#include <ccan/str/hex/hex.h>
+
+const char extended_tx[] = "02000000000101b5bef485c41d0d1f58d1e8a561924ece5c476d86cff063ea10c8df06136eb31d00000000171600144aa38e396e1394fb45cbf83f48d1464fbc9f498fffffffff0140330f000000000017a9140580ba016669d3efaf09a0b2ec3954469ea2bf038702483045022100f2abf9e9cf238c66533af93f23937eae8ac01fb6f105a00ab71dbefb9637dc9502205c1ac745829b3f6889607961f5d817dfa0c8f52bdda12e837c4f7b162f6db8a701210204096eb817f7efb414ef4d3d8be39dd04374256d3b054a322d4a6ee22736d03b00000000";
+
+static void hexeq(const void *p, size_t len, const char *hex)
+{
+	char *tmphex = tal_arr(NULL, char, hex_str_size(len));
+	hex_encode(p, len, tmphex, tal_count(tmphex));
+
+	if (strcmp(hex, tmphex)) {
+		fprintf(stderr, "Expected '%s' got '%s'", hex, tmphex);
+		abort();
+	}
+	tal_free(tmphex);
+}
+
+static void tal_hexeq(const u8 *p, const char *hex)
+{
+	hexeq(p, tal_count(p),hex);
+}
+
+int main(void)
+{
+	struct bitcoin_tx *tx;
+
+	tx = bitcoin_tx_from_hex(NULL, extended_tx, strlen(extended_tx));
+	assert(tx);
+
+	/* Canonical results from Nichola Dorier's
+	 *	   http://n.bitcoin.ninja/checktx
+	 * With much thanks!
+	 */
+	assert(tx->input_count == 1);
+	assert(tx->output_count == 1);
+
+	reverse_bytes(tx->input[0].txid.sha.u.u8, sizeof(tx->input[0].txid));
+	hexeq(&tx->input[0].txid, sizeof(tx->input[0].txid),
+	      "1db36e1306dfc810ea63f0cf866d475cce4e9261a5e8d1581f0d1dc485f4beb5");
+	assert(tx->input[0].index == 0);
+
+	/* This is a p2sh-p2wpkh: */
+	/* ScriptSig is push of "version 0 + hash of pubkey" */
+	hexeq(tx->input[0].script, tx->input[0].script_length,
+	      "16" "00" "144aa38e396e1394fb45cbf83f48d1464fbc9f498f");
+
+	/* Witness with 2 items */
+	assert(tx->input[0].witness);
+	assert(tal_count(tx->input[0].witness) == 2);
+
+	tal_hexeq(tx->input[0].witness[0],
+		  "3045022100f2abf9e9cf238c66533af93f23937eae8ac01fb6f105a00ab71dbefb9637dc9502205c1ac745829b3f6889607961f5d817dfa0c8f52bdda12e837c4f7b162f6db8a701");
+	tal_hexeq(tx->input[0].witness[1],
+		  "0204096eb817f7efb414ef4d3d8be39dd04374256d3b054a322d4a6ee22736d03b");
+
+	tal_free(tx);
+	return 0;
+}