diff --git a/.covignore b/.covignore
index 016f806..8c36f6f 100644
--- a/.covignore
+++ b/.covignore
@@ -1 +1,2 @@
 /tests/
+node_modules/
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3eeddb7
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+node_modules
+my_test
diff --git a/.npmignore b/.npmignore
new file mode 100644
index 0000000..d69ed3a
--- /dev/null
+++ b/.npmignore
@@ -0,0 +1,4 @@
+my_test
+covreporter
+build
+tests
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a26e2e6..39cfe31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# v0.2.1 / 2015-04-03
+
+* Support AMD.
+
 # v0.2.0 / 2015-02-28
 
 * Remove ascii parameter.
diff --git a/README.md b/README.md
index 82861b2..cada568 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,12 @@ If you use node.js, you should require the module first:
 ```JavaScript
 md2 = require('js-md2');
 ```
+If you use require.js, you should require the module first:
+```JavaScript
+require(['md2.js'], function(md2) {
+  // ...
+});
+```
 
 ## Example
 Code
diff --git a/bower.json b/bower.json
index b7693e0..99276b0 100644
--- a/bower.json
+++ b/bower.json
@@ -1,7 +1,7 @@
 {
   "name": "js-md2",
-  "version": "0.2.0",
-  "main": ["build/md2.min.js"],
+  "version": "0.2.1",
+  "main": ["src/md2.js"],
   "ignore": [
     "samples",
     "tests"
diff --git a/build/md2.min.js b/build/md2.min.js
index 7293498..073eeb7 100644
--- a/build/md2.min.js
+++ b/build/md2.min.js
@@ -1,5 +1,5 @@
 /*
- * js-md5 v0.2.0
+ * js-md5 v0.2.1
  * https://github.com/emn178/js-md2
  *
  * Copyright 2014-2015, emn178@gmail.com
@@ -7,8 +7,8 @@
  * Licensed under the MIT license:
  * http://www.opensource.org/licenses/MIT
  */
-(function(e,v){var n="undefined"!=typeof module;n&&(e=global);var t="0123456789abcdef".split(""),u=[41,46,67,201,162,216,124,1,61,54,84,161,236,240,6,19,98,167,5,243,192,199,115,140,152,147,43,217,188,76,130,202,30,155,87,60,253,212,224,22,103,66,111,24,138,23,229,18,190,78,196,214,218,158,222,73,160,251,245,142,187,47,238,122,169,104,121,145,21,178,7,63,148,194,16,137,11,34,95,33,128,127,93,154,90,144,50,39,53,62,204,231,191,247,151,3,255,25,48,179,72,165,181,209,215,94,146,42,172,86,170,198,79,
-184,56,210,150,164,125,182,118,252,107,226,156,116,4,241,69,157,112,89,100,113,135,32,134,91,207,101,230,45,168,2,27,96,37,173,174,176,185,246,28,70,97,105,52,64,126,15,85,71,163,35,221,81,175,58,195,92,249,206,186,197,234,38,44,83,13,110,133,40,132,9,211,223,205,244,65,129,77,82,106,220,55,200,108,193,171,250,36,225,123,8,12,189,177,74,120,136,149,139,227,99,232,109,233,203,213,254,59,0,29,57,242,239,183,14,102,88,208,228,166,119,114,248,235,117,75,10,49,68,80,180,143,237,31,26,219,153,141,51,159,
-17,131,20],c=[],a=[],h=[],m=function(e,n){var d,b,k,f,g=0,p=1,l=0,q=0,r=0,m=e.length;for(b=0;16>b;++b)a[b]=h[b]=0;c[16]=c[17]=c[18]=0;do{c[0]=c[16];c[1]=c[17];c[2]=c[18];c[16]=c[17]=c[18]=c[3]=c[4]=c[5]=c[6]=c[7]=c[8]=c[9]=c[10]=c[11]=c[12]=c[13]=c[14]=c[15]=0;for(b=q;l<m&&16>b;++l)d=e.charCodeAt(l),128>d?c[b++]=d:(2048>d?c[b++]=192|d>>6:(55296>d||57344<=d?c[b++]=224|d>>12:(d=65536+((d&1023)<<10|e.charCodeAt(++l)&1023),c[b++]=240|d>>18,c[b++]=128|d>>12&63),c[b++]=128|d>>6&63),c[b++]=128|d&63);r+=
-b-q;q=b-16;if(l==m&&16>b)for(p=2,f=16-(r&15);16>b;++b)c[b]=f;for(b=0;16>b;++b)h[b]^=u[c[b]^g],g=h[b];for(b=0;b<p;++b)for(d=0===b?c:h,a[16]=d[0],a[32]=a[16]^a[0],a[17]=d[1],a[33]=a[17]^a[1],a[18]=d[2],a[34]=a[18]^a[2],a[19]=d[3],a[35]=a[19]^a[3],a[20]=d[4],a[36]=a[20]^a[4],a[21]=d[5],a[37]=a[21]^a[5],a[22]=d[6],a[38]=a[22]^a[6],a[23]=d[7],a[39]=a[23]^a[7],a[24]=d[8],a[40]=a[24]^a[8],a[25]=d[9],a[41]=a[25]^a[9],a[26]=d[10],a[42]=a[26]^a[10],a[27]=d[11],a[43]=a[27]^a[11],a[28]=d[12],a[44]=a[28]^a[12],
-a[29]=d[13],a[45]=a[29]^a[13],a[30]=d[14],a[46]=a[30]^a[14],a[31]=d[15],a[47]=a[31]^a[15],d=f=0;18>d;++d){for(k=0;48>k;++k)a[k]=f=a[k]^u[f];f=f+d&255}}while(1==p);g="";for(b=0;16>b;++b)g+=t[a[b]>>4&15]+t[a[b]&15];return g};!e.JS_MD2_TEST&&n?module.exports=m:e&&(e.md2=m)})(this);
+(function(h,v){"object"==typeof process&&process.versions&&process.versions.node&&(h=global);var u="function"==typeof define&&define.amd,q="0123456789abcdef".split(""),r=[41,46,67,201,162,216,124,1,61,54,84,161,236,240,6,19,98,167,5,243,192,199,115,140,152,147,43,217,188,76,130,202,30,155,87,60,253,212,224,22,103,66,111,24,138,23,229,18,190,78,196,214,218,158,222,73,160,251,245,142,187,47,238,122,169,104,121,145,21,178,7,63,148,194,16,137,11,34,95,33,128,127,93,154,90,144,50,39,53,62,204,231,191,
+247,151,3,255,25,48,179,72,165,181,209,215,94,146,42,172,86,170,198,79,184,56,210,150,164,125,182,118,252,107,226,156,116,4,241,69,157,112,89,100,113,135,32,134,91,207,101,230,45,168,2,27,96,37,173,174,176,185,246,28,70,97,105,52,64,126,15,85,71,163,35,221,81,175,58,195,92,249,206,186,197,234,38,44,83,13,110,133,40,132,9,211,223,205,244,65,129,77,82,106,220,55,200,108,193,171,250,36,225,123,8,12,189,177,74,120,136,149,139,227,99,232,109,233,203,213,254,59,0,29,57,242,239,183,14,102,88,208,228,166,
+119,114,248,235,117,75,10,49,68,80,180,143,237,31,26,219,153,141,51,159,17,131,20],c=[],a=[],k=[],g=function(e){var d,b,l,f,h=0,g=1,m=0,n=0,p=0,t=e.length;for(b=0;16>b;++b)a[b]=k[b]=0;c[16]=c[17]=c[18]=0;do{c[0]=c[16];c[1]=c[17];c[2]=c[18];c[16]=c[17]=c[18]=c[3]=c[4]=c[5]=c[6]=c[7]=c[8]=c[9]=c[10]=c[11]=c[12]=c[13]=c[14]=c[15]=0;for(b=n;m<t&&16>b;++m)d=e.charCodeAt(m),128>d?c[b++]=d:(2048>d?c[b++]=192|d>>6:(55296>d||57344<=d?c[b++]=224|d>>12:(d=65536+((d&1023)<<10|e.charCodeAt(++m)&1023),c[b++]=240|
+d>>18,c[b++]=128|d>>12&63),c[b++]=128|d>>6&63),c[b++]=128|d&63);p+=b-n;n=b-16;if(m==t&&16>b)for(g=2,f=16-(p&15);16>b;++b)c[b]=f;for(b=0;16>b;++b)k[b]^=r[c[b]^h],h=k[b];for(b=0;b<g;++b)for(d=0===b?c:k,a[16]=d[0],a[32]=a[16]^a[0],a[17]=d[1],a[33]=a[17]^a[1],a[18]=d[2],a[34]=a[18]^a[2],a[19]=d[3],a[35]=a[19]^a[3],a[20]=d[4],a[36]=a[20]^a[4],a[21]=d[5],a[37]=a[21]^a[5],a[22]=d[6],a[38]=a[22]^a[6],a[23]=d[7],a[39]=a[23]^a[7],a[24]=d[8],a[40]=a[24]^a[8],a[25]=d[9],a[41]=a[25]^a[9],a[26]=d[10],a[42]=a[26]^
+a[10],a[27]=d[11],a[43]=a[27]^a[11],a[28]=d[12],a[44]=a[28]^a[12],a[29]=d[13],a[45]=a[29]^a[13],a[30]=d[14],a[46]=a[30]^a[14],a[31]=d[15],a[47]=a[31]^a[15],d=f=0;18>d;++d){for(l=0;48>l;++l)a[l]=f=a[l]^r[f];f=f+d&255}}while(1==g);e="";for(b=0;16>b;++b)e+=q[a[b]>>4&15]+q[a[b]&15];return e};!h.JS_MD2_TEST&&"object"==typeof module&&module.exports?module.exports=g:(u&&define(function(){return g}),h.md2=g)})(this);
diff --git a/package.json b/package.json
index 71f7633..47ffc61 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "js-md2",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "A simple MD2 hash function for JavaScript supports UTF-8 encoding.",
   "main": "src/md2.js",
   "devDependencies": {
diff --git a/src/md2.js b/src/md2.js
index 1abd29d..28c0c0a 100644
--- a/src/md2.js
+++ b/src/md2.js
@@ -1,5 +1,5 @@
 /*
- * js-md5 v0.2.0
+ * js-md5 v0.2.1
  * https://github.com/emn178/js-md2
  *
  * Copyright 2014-2015, emn178@gmail.com
@@ -10,10 +10,12 @@
 ;(function(root, undefined) {
   'use strict';
 
-  var NODE_JS = typeof(module) != 'undefined';
+  var NODE_JS = typeof process == 'object' && process.versions && process.versions.node;
   if(NODE_JS) {
     root = global;
   }
+  var COMMON_JS = !root.JS_MD2_TEST && typeof module == 'object' && module.exports;
+  var AMD = typeof define == 'function' && define.amd;
   var HEX_CHARS = '0123456789abcdef'.split('');
 
   var S = [ 0x29, 0x2E, 0x43, 0xC9, 0xA2, 0xD8, 0x7C, 0x01, 0x3D, 0x36, 0x54, 0xA1, 0xEC, 0xF0, 0x06, 0x13,
@@ -35,7 +37,7 @@
 
   var M = [], X = [], C = [];
 
-  var md2 = function(message, asciiOnly) {
+  var md2 = function(message) {
     var code, i, j, k, t, L = 0, loop = 1, B,
         index = 0, start = 0, bytes = 0, length = message.length;
 
@@ -140,9 +142,14 @@
     return hex;
   };
   
-  if(!root.JS_MD2_TEST && NODE_JS) {
+  if(COMMON_JS) {
     module.exports = md2;
-  } else if(root) {
+  } else {
+    if(AMD) {
+      define(function() {
+        return md2;
+      });
+    }
     root.md2 = md2;
   }
 }(this));
diff --git a/tests/node-test.js b/tests/node-test.js
index 907e291..65035cc 100644
--- a/tests/node-test.js
+++ b/tests/node-test.js
@@ -9,3 +9,15 @@ md2 = null
 JS_MD2_TEST = true;
 require('../src/md2.js');
 require('./test.js');
+
+delete require.cache[require.resolve('../src/md2.js')]
+delete require.cache[require.resolve('./test.js')]
+md2 = null
+
+define = function(func) {
+  md2 = func();
+};
+define.amd = true;
+
+require('../src/md2.js');
+require('./test.js');
diff --git a/tests/requirejs.html b/tests/requirejs.html
new file mode 100644
index 0000000..dd721e3
--- /dev/null
+++ b/tests/requirejs.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>MD2</title>
+  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/mocha/2.1.0/mocha.min.css">
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/mocha/2.1.0/mocha.min.js"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/expect.js/0.2.0/expect.min.js"></script>
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.1.17/require.min.js"></script>
+</head>
+<body>
+  <div id="mocha"></div>
+  <script>
+    mocha.setup('bdd');
+    require(['../src/md2.js'], function(md2) {
+      window.md2 = md2;
+      require(['test.js'], function() {
+        mocha.checkLeaks();
+        mocha.run();
+      })
+    });
+  </script>
+</body>
+</html>