diff --git a/lib/binarypack.js b/lib/binarypack.js
index 91a7a3f..208545b 100644
--- a/lib/binarypack.js
+++ b/lib/binarypack.js
@@ -212,7 +212,7 @@ BinaryPack.Packer.prototype.pack_bin = function(blob){
 }
 
 BinaryPack.Packer.prototype.pack_string = function(str){
-  var length = str.length;
+  var length = Buffer.byteLength(str);
   if (length <= 0x0f){
     this.bufferBuilder.append(0xb0 + length, 2);
   } else if (length <= 0xffff){
diff --git a/lib/bufferbuilder.js b/lib/bufferbuilder.js
index a0bd8d4..dd8bb0c 100644
--- a/lib/bufferbuilder.js
+++ b/lib/bufferbuilder.js
@@ -21,13 +21,16 @@ BufferBuilder.prototype.append = function(data, type) {
   // 7: Int32
   // 8: Float
   // 9: Double
-  
-  if(type < 2) {
-    this._length += data.length;
-  } else {
-    this._length += this._sizes[type];
-  }
-  
+  switch(type) {
+    case 0:
+      this._length += Buffer.byteLength(data);
+      break;
+    case 1: 
+      this._length += data.length;
+      break;
+    default:
+      this._length += this._sizes[type];
+  };
   this._pieces.push([data, type]);
 };
 
@@ -55,7 +58,7 @@ BufferBuilder.prototype.getBuffer = function() {
         cursor.writeUInt32BE(tuple[0]);
         break;
       case 5:
-        cursor.writeInt8BE(tuple[0]);
+        cursor.writeInt8(tuple[0]);
         break;
       case 6:
         cursor.writeInt16BE(tuple[0]);
diff --git a/package.json b/package.json
index 4d429bd..29869d4 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "binarypack",
 	"description": "BinaryPack is a JSON-like binary serialization format",
-  "version": "0.0.2",
+  "version": "0.0.4",
 	"homepage": "https://github.com/binaryjs/node-binarypack",
 	"author": "Eric Zhang",
 	"repository": {