diff --git a/AUTHORS b/AUTHORS
index b50c216..8bfab83 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1,2 +1,3 @@
 Luke Dashjr <luke_libblkmaker@dashjr.org>
 Andy Alness <andy.alness@gmail.com>
+Huang Le <4tarhl@gmail.com>
diff --git a/blkmaker.c b/blkmaker.c
index 8e01c6c..6aede42 100644
--- a/blkmaker.c
+++ b/blkmaker.c
@@ -47,6 +47,32 @@ bool _blkmk_dblsha256(void *hash, const void *data, size_t datasz) {
 
 #define dblsha256 _blkmk_dblsha256
 
+static
+size_t varintDecode(const uint8_t *p, size_t size, uint64_t *n)
+{
+	if (size > 8 && p[0] == 0xff)
+	{
+		*n = upk_u64le(p, 1);
+		return 9;
+	}
+	if (size > 4 && p[0] == 0xfe)
+	{
+		*n = upk_u32le(p, 1);
+		return 5;
+	}
+	if (size > 2 && p[0] == 0xfd)
+	{
+		*n = upk_u16le(p, 1);
+		return 3;
+	}
+	if (size > 0 && p[0] <= 0xfc)
+	{
+		*n = p[0];
+		return 1;
+	}
+	return 0;
+}
+
 static
 char varintEncode(unsigned char *out, uint64_t n) {
 	if (n < 0xfd)