diff --git a/bip32.c b/bip32.c
index a37041e48..5acfd6d59 100644
--- a/bip32.c
+++ b/bip32.c
@@ -7,30 +7,44 @@
 #include "sha2.h"
 #include "ripemd160.h"
 
-uint8_t hdnode_coin_version = 0x00;
-
-void hdnode_from_pub(uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *public_key, HDNode *out)
+void hdnode_from_xpub(uint8_t version_byte, uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *public_key, HDNode *out)
 {
 	out->version = version;
 	out->depth = depth;
 	out->fingerprint = fingerprint;
 	out->child_num = child_num;
-	memset(out->private_key, 0, 32);
 	memcpy(out->chain_code, chain_code, 32);
+	memset(out->private_key, 0, 32);
 	memcpy(out->public_key, public_key, 33);
+	out->version_byte = version_byte;
 	hdnode_fill_address(out);
 }
 
-void hdnode_from_seed(uint8_t *seed, int seed_len, HDNode *out)
+void hdnode_from_xprv(uint8_t version_byte, uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *private_key, HDNode *out)
 {
-	out->version = 0x0488ADE4; // main-net
+	out->version = version;
+	out->depth = depth;
+	out->fingerprint = fingerprint;
+	out->child_num = child_num;
+	memcpy(out->chain_code, chain_code, 32);
+	memcpy(out->private_key, private_key, 32);
+	hdnode_fill_public_key(out);
+	out->version_byte = version_byte;
+	hdnode_fill_address(out);
+}
+
+void hdnode_from_seed(uint8_t version_byte, uint32_t version, uint8_t *seed, int seed_len, HDNode *out)
+{
+	uint8_t I[32 + 32];
+	out->version = version;
 	out->depth = 0;
 	out->fingerprint = 0x00000000;
 	out->child_num = 0;
-	// this can be done because private_key[32] and chain_code[32]
-	// form a continuous 64 byte block in the memory
-	hmac_sha512((uint8_t *)"Bitcoin seed", 12, seed, seed_len, out->private_key);
+	hmac_sha512((uint8_t *)"Bitcoin seed", 12, seed, seed_len, I);
+	memcpy(out->chain_code, I + 32, 32);
+	memcpy(out->private_key, I, 32);
 	hdnode_fill_public_key(out);
+	out->version_byte = version_byte;
 	hdnode_fill_address(out);
 }
 
@@ -56,8 +70,8 @@ int hdnode_private_ckd(HDNode *inout, uint32_t i)
 	bn_read_be(inout->private_key, &a);
 
 	hmac_sha512(inout->chain_code, 32, data, sizeof(data), I);
-	memcpy(inout->private_key, I, 32);
 	memcpy(inout->chain_code, I + 32, 32);
+	memcpy(inout->private_key, I, 32);
 
 	bn_read_be(inout->private_key, &b);
 	bn_addmod(&a, &b, &order256k1);
@@ -110,12 +124,12 @@ int hdnode_public_ckd(HDNode *inout, uint32_t i)
 	return 1;
 }
 
-void hdnode_fill_public_key(HDNode *xprv)
+void hdnode_fill_public_key(HDNode *node)
 {
-	ecdsa_get_public_key33(xprv->private_key, xprv->public_key);
+	ecdsa_get_public_key33(node->private_key, node->public_key);
 }
 
-void hdnode_fill_address(HDNode *xprv)
+void hdnode_fill_address(HDNode *node)
 {
-	ecdsa_get_address(xprv->public_key, hdnode_coin_version, xprv->address);
+	ecdsa_get_address(node->public_key, node->version_byte, node->address);
 }
diff --git a/bip32.h b/bip32.h
index 605b182f6..a49ba8519 100644
--- a/bip32.h
+++ b/bip32.h
@@ -8,17 +8,18 @@ typedef struct {
 	uint32_t depth;
 	uint32_t fingerprint;
 	uint32_t child_num;
-	uint8_t private_key[32];
 	uint8_t chain_code[32];
+	uint8_t private_key[32];
 	uint8_t public_key[33];
+	uint8_t version_byte;
 	char address[35];
 } HDNode;
 
-extern uint8_t hdnode_coin_version;
+void hdnode_from_xpub(uint8_t version_byte, uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *public_key, HDNode *out);
 
-void hdnode_from_pub(uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *public_key, HDNode *out);
+void hdnode_from_xprv(uint8_t version_byte, uint32_t version, uint32_t depth, uint32_t fingerprint, uint32_t child_num, uint8_t *chain_code, uint8_t *private_key, HDNode *out);
 
-void hdnode_from_seed(uint8_t *seed, int seed_len, HDNode *out);
+void hdnode_from_seed(uint8_t version_byte, uint32_t version, uint8_t *seed, int seed_len, HDNode *out);
 
 #define hdnode_private_ckd_prime(X, I) hdnode_private_ckd((X), ((I) | 0x80000000))
 
@@ -26,8 +27,8 @@ int hdnode_private_ckd(HDNode *inout, uint32_t i);
 
 int hdnode_public_ckd(HDNode *inout, uint32_t i);
 
-void hdnode_fill_public_key(HDNode *xprv);
+void hdnode_fill_public_key(HDNode *node);
 
-void hdnode_fill_address(HDNode *xprv);
+void hdnode_fill_address(HDNode *node);
 
 #endif
diff --git a/tests.c b/tests.c
index 8ec319d0e..779657e89 100644
--- a/tests.c
+++ b/tests.c
@@ -80,7 +80,7 @@ START_TEST(test_bip32_vector_1)
 	HDNode node;
 
 	// init m
-	hdnode_from_seed(fromhex("000102030405060708090a0b0c0d0e0f"), 16, &node);
+	hdnode_from_seed(0x00, 0x0488B21E, fromhex("000102030405060708090a0b0c0d0e0f"), 16, &node);
 
 	// [Chain m]
 	ck_assert_int_eq(node.fingerprint, 0x00000000);
@@ -138,7 +138,7 @@ START_TEST(test_bip32_vector_2)
 	int r;
 
 	// init m
-	hdnode_from_seed(fromhex("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542"), 64, &node);
+	hdnode_from_seed(0x00, 0x0488B21E, fromhex("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542"), 64, &node);
 
 	// [Chain m]
 	ck_assert_int_eq(node.fingerprint, 0x00000000);
@@ -193,7 +193,7 @@ START_TEST(test_bip32_vector_2)
 	ck_assert_str_eq(node.address,     "14UKfRV9ZPUp6ZC9PLhqbRtxdihW9em3xt");
 
 	// init m
-	hdnode_from_seed(fromhex("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542"), 64, &node);
+	hdnode_from_seed(0x00, 0x0488B21E, fromhex("fffcf9f6f3f0edeae7e4e1dedbd8d5d2cfccc9c6c3c0bdbab7b4b1aeaba8a5a29f9c999693908d8a8784817e7b7875726f6c696663605d5a5754514e4b484542"), 64, &node);
 
 	// test public derivation
 	// [Chain m/0]