diff --git a/bitcoin/block.c b/bitcoin/block.c
index 861dc5607..81b575399 100644
--- a/bitcoin/block.c
+++ b/bitcoin/block.c
@@ -5,8 +5,9 @@
 #include <common/type_to_string.h>
 
 /* Encoding is <blockhdr> <varint-num-txs> <tx>... */
-struct bitcoin_block *bitcoin_block_from_hex(const tal_t *ctx,
-					     const char *hex, size_t hexlen)
+struct bitcoin_block *
+bitcoin_block_from_hex(const tal_t *ctx, const struct chainparams *chainparams,
+		       const char *hex, size_t hexlen)
 {
 	struct bitcoin_block *b;
 	u8 *linear_tx;
@@ -28,8 +29,10 @@ struct bitcoin_block *bitcoin_block_from_hex(const tal_t *ctx,
 	pull(&p, &len, &b->hdr, sizeof(b->hdr));
 	num = pull_varint(&p, &len);
 	b->tx = tal_arr(b, struct bitcoin_tx *, num);
-	for (i = 0; i < num; i++)
+	for (i = 0; i < num; i++) {
 		b->tx[i] = pull_bitcoin_tx(b->tx, &p, &len);
+		b->tx[i]->chainparams = chainparams;
+	}
 
 	/* We should end up not overrunning, nor have extra */
 	if (!p || len)
diff --git a/bitcoin/block.h b/bitcoin/block.h
index ec96fc9d7..106ba0edb 100644
--- a/bitcoin/block.h
+++ b/bitcoin/block.h
@@ -8,6 +8,8 @@
 #include <ccan/tal/tal.h>
 #include <stdbool.h>
 
+struct chainparams;
+
 struct bitcoin_blkid {
 	struct sha256_double shad;
 };
@@ -29,8 +31,9 @@ struct bitcoin_block {
 	struct bitcoin_tx **tx;
 };
 
-struct bitcoin_block *bitcoin_block_from_hex(const tal_t *ctx,
-					     const char *hex, size_t hexlen);
+struct bitcoin_block *
+bitcoin_block_from_hex(const tal_t *ctx, const struct chainparams *chainparams,
+		       const char *hex, size_t hexlen);
 
 /* Parse hex string to get blockid (reversed, a-la bitcoind). */
 bool bitcoin_blkid_from_hex(const char *hexstr, size_t hexstr_len,
diff --git a/bitcoin/test/Makefile b/bitcoin/test/Makefile
index 5e8e5ba54..d79186fff 100644
--- a/bitcoin/test/Makefile
+++ b/bitcoin/test/Makefile
@@ -4,7 +4,7 @@ BITCOIN_TEST_PROGRAMS := $(BITCOIN_TEST_OBJS:.o=)
 
 BITCOIN_TEST_COMMON_OBJS := common/utils.o
 
-$(BITCOIN_TEST_PROGRAMS): $(CCAN_OBJS) $(BITCOIN_TEST_COMMON_OBJS)
+$(BITCOIN_TEST_PROGRAMS): $(CCAN_OBJS) $(BITCOIN_TEST_COMMON_OBJS) bitcoin/chainparams.o
 $(BITCOIN_TEST_OBJS): $(CCAN_HEADERS) $(BITCOIN_HEADERS) $(BITCOIN_SRC)
 
 ALL_TEST_PROGRAMS += $(BITCOIN_TEST_PROGRAMS)
diff --git a/bitcoin/test/run-bitcoin_block_from_hex.c b/bitcoin/test/run-bitcoin_block_from_hex.c
index 5b5bd3362..5246024a0 100644
--- a/bitcoin/test/run-bitcoin_block_from_hex.c
+++ b/bitcoin/test/run-bitcoin_block_from_hex.c
@@ -69,7 +69,8 @@ int main(void)
 	struct bitcoin_block *b;
 
 	setup_locale();
-	b = bitcoin_block_from_hex(NULL, block, strlen(block));
+	b = bitcoin_block_from_hex(NULL, chainparams_for_network("bitcoin"),
+				   block, strlen(block));
 
 	assert(b);
 	assert(b->hdr.version == CPU_TO_LE32(0x6592a000));
diff --git a/lightningd/bitcoind.c b/lightningd/bitcoind.c
index 09340224a..2dc85f072 100644
--- a/lightningd/bitcoind.c
+++ b/lightningd/bitcoind.c
@@ -469,7 +469,8 @@ static bool process_rawblock(struct bitcoin_cli *bcli)
 		   struct bitcoin_block *blk,
 		   void *arg) = bcli->cb;
 
-	blk = bitcoin_block_from_hex(bcli, bcli->output, bcli->output_bytes);
+	blk = bitcoin_block_from_hex(bcli, bcli->bitcoind->chainparams,
+				     bcli->output, bcli->output_bytes);
 	if (!blk)
 		fatal("%s: bad block '%.*s'?",
 		      bcli_args(tmpctx, bcli),