diff --git a/.gitignore b/.gitignore
index f124bd2..28c9018 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ results
 
 node_modules
 npm-debug.log
+.editorconfig
diff --git a/.travis.yml b/.travis.yml
index b2c1c5e..498da6d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,6 @@
 sudo: false
 language: node_js
 node_js:
-  - '0.10'
-  - '0.11'
-  - '0.12'
-  - '4'
-  - '6'
-  - '7'
+  - '8'
+  - '10'
 script: npm run test-travis
diff --git a/lib/formstream.js b/lib/formstream.js
index e7f39ce..d8dfedd 100644
--- a/lib/formstream.js
+++ b/lib/formstream.js
@@ -1,293 +1,279 @@
-/**
- * Data format:
- *
-
---FormStreamBoundary1349886663601\r\n
-Content-Disposition: form-data; name="foo"\r\n
-\r\n
-<FIELD-CONTENT>\r\n
---FormStreamBoundary1349886663601\r\n
-Content-Disposition: form-data; name="file"; filename="formstream.test.js"\r\n
-Content-Type: application/javascript\r\n
-\r\n
-<FILE-CONTENT>\r\n
---FormStreamBoundary1349886663601\r\n
-Content-Disposition: form-data; name="pic"; filename="fawave.png"\r\n
-Content-Type: image/png\r\n
-\r\n
-<IMAGE-CONTENT>\r\n
---FormStreamBoundary1349886663601--
-
- *
- */
-
 'use strict';
 
-var Stream = require('stream');
-var parseStream = require('pause-stream');
-var util = require('util');
-var mime = require('mime');
-var path = require('path');
-var fs = require('fs');
-var destroy = require('destroy');
-
-var PADDING = '--';
-var NEW_LINE = '\r\n';
-var NEW_LINE_BUFFER = new Buffer(NEW_LINE);
-
-function FormStream() {
-  if (!(this instanceof FormStream)) {
-    return new FormStream();
-  }
+const fs = require('fs');
+const path = require('path');
+const { Readable } = require('stream');
 
-  FormStream.super_.call(this);
+const debug = require('debug')('formstream');
+const destroy = require('destroy');
+const mime = require('mime');
 
-  this._boundary = this._generateBoundary();
-  this._streams = [];
-  this._buffers = [];
-  this._endData = new Buffer(PADDING + this._boundary + PADDING + NEW_LINE);
-  this._contentLength = 0;
-  this._isAllStreamSizeKnown = true;
-  this._knownStreamSize = 0;
-}
+const PADDING = '--';
+const NEW_LINE = '\r\n';
+const NEW_LINE_BUFFER = Buffer.from(NEW_LINE);
 
-util.inherits(FormStream, Stream);
-module.exports = FormStream;
+class FormStream extends Readable {
+  constructor() {
+    super();
 
-FormStream.prototype._generateBoundary = function() {
-  // https://github.com/felixge/node-form-data/blob/master/lib/form_data.js#L162
-  // This generates a 50 character boundary similar to those used by Firefox.
-  // They are optimized for boyer-moore parsing.
-  var boundary = '--------------------------';
-  for (var i = 0; i < 24; i++) {
-    boundary += Math.floor(Math.random() * 10).toString(16);
-  }
+    this._boundary = this._generateBoundary();
+    this._streams = [];
+    this._buffers = [];
+    this._contentLength = 0;
+    this._isAllStreamSizeKnown = true;
+    this._knownStreamSize = 0;
 
-  return boundary;
-};
+    this._eachEnd = null;
 
-FormStream.prototype.setTotalStreamSize = function (size) {
-  // this method should not make any sense if the length of each stream is known.
-  if (this._isAllStreamSizeKnown) {
-    return this;
-  }
+    this._endData = Buffer.from(`${PADDING}${this._boundary}${PADDING}${NEW_LINE}`);
 
-  size = size || 0;
-
-  for (var i = 0; i < this._streams.length; i++) {
-    size += this._streams[i][0].length;
-    size += NEW_LINE_BUFFER.length; // stream field end pedding size
+    this._currentStream = null;
+    this._readingOneStream = false;
   }
 
-  this._knownStreamSize = size;
-  this._isAllStreamSizeKnown = true;
-
-  return this;
-};
+  _read() {
+    if (this._readingOneStream) {
+      debug('> still reading...');
+      return;
+    }
 
-FormStream.prototype.headers = function (options) {
-  var headers = {
-    'Content-Type': 'multipart/form-data; boundary=' + this._boundary
-  };
+    if (this._buffers && this._buffers.length) {
+      debug('pushing buffers...');
+      for (const buf of this._buffers) {
+        this.push(buf[0]);
+        this.push(buf[1]);
+        this.push(NEW_LINE_BUFFER);
+      }
+      this._buffers = [];
+    }
 
-  // calculate total stream size
-  this._contentLength += this._knownStreamSize;
+    this._tryNextStream();
+  }
 
-  // calculate length of end padding
-  this._contentLength += this._endData.length;
+  _tryNextStream() {
+    if (this._readingOneStream) return;
+    this._readingOneStream = true;
+
+    debug('start read...');
+    const item = this._streams.shift();
+    if (!item) {
+      debug('no more stream');
+      this.push(this._endData);
+      this.push(null);
+      this._readingOneStream = false;
+      return;
+    }
 
-  if (this._isAllStreamSizeKnown) {
-    headers['Content-Length'] = String(this._contentLength);
+    debug('push leading...');
+    this.push(item[0]);
+    
+    const stream = item[1];
+    this._currentStream = stream;
+
+    stream.on('end', () => {
+      debug('end chunk');
+      this._currentStream = null;
+      this.push(NEW_LINE_BUFFER);
+      debug('set reading = false');
+      this._readingOneStream = false;
+      if (stream.destroy) stream.destroy();
+      this._tryNextStream();
+    });
+
+    stream.on('data', data => {
+      this.push(data);
+      debug('data chunk >', data.length);
+      stream.resume();
+    });
+
+    if (stream.resume) {
+      stream.resume();
+      debug('stream resume');
+    }
   }
 
-  if (options) {
-    for (var k in options) {
-      headers[k] = options[k];
+  _generateBoundary() {
+    // https://github.com/felixge/node-form-data/blob/master/lib/form_data.js#L162
+    // This generates a 50 character boundary similar to those used by Firefox.
+    // They are optimized for boyer-moore parsing.
+    let boundary = '--------------------------';
+    for (let i = 0; i < 24; i++) {
+      boundary += Math.floor(Math.random() * 10).toString(16);
     }
+    return boundary;
   }
 
-  return headers;
-};
-
-FormStream.prototype.file = function (name, filepath, filename, filesize) {
-  var mimeType = mime.lookup(filepath);
+  setTotalStreamSize(size) {
+    // this method should not make any sense if the length of each stream is known.
+    if (this._isAllStreamSizeKnown) {
+      return this;
+    }
 
-  if (typeof filename === 'number' && !filesize) {
-    filesize = filename;
-    filename = path.basename(filepath);
-  } else if (!filename) {
-    filename = path.basename(filepath);
-  }
+    size = size || 0;
 
-  var stream = fs.createReadStream(filepath);
-
-  return this.stream(name, stream, filename, mimeType, filesize);
-};
-
-/**
- * Add a form field
- * @param  {String} name field name
- * @param  {String|Buffer} value field value
- * @return {this}
- */
-FormStream.prototype.field = function (name, value) {
-  if (!Buffer.isBuffer(value)) {
-    // field(String, Number)
-    // https://github.com/qiniu/nodejs-sdk/issues/123
-    if (typeof value === 'number') {
-      value = String(value);
+    for (let i = 0; i < this._streams.length; i++) {
+      size += this._streams[i][0].length;
+      size += NEW_LINE_BUFFER.length; // stream field end pedding size
     }
-    value = new Buffer(value);
-  }
-  return this.buffer(name, value);
-};
-
-FormStream.prototype.stream = function (name, stream, filename, mimeType, size) {
-  if (typeof mimeType === 'number' && !size) {
-    size = mimeType;
-    mimeType = mime.lookup(filename);
-  } else if (!mimeType) {
-    mimeType = mime.lookup(filename);
+
+    this._knownStreamSize = size;
+    this._isAllStreamSizeKnown = true;
+
+    return this;
   }
 
-  stream.once('error', this.emit.bind(this, 'error'));
-  // if form stream destroy, also destroy the source stream
-  this.once('destroy', function () {
-    destroy(stream);
-  });
+  headers(options) {
+    const headers = {
+      'Content-Type': `multipart/form-data; boundary=${this._boundary}`,
+    };
+
+    // calculate total stream size
+    this._contentLength += this._knownStreamSize;
 
-  var leading = this._leading({ name: name, filename: filename }, mimeType);
+    // calculate length of end padding
+    this._contentLength += this._endData.length;
 
-  var ps = parseStream().pause();
-  stream.pipe(ps);
+    if (this._isAllStreamSizeKnown) {
+      headers['Content-Length'] = this._contentLength.toString();
+    }
 
-  this._streams.push([leading, ps]);
+    if (options) {
+      for (const k in options) {
+        if (!options.hasOwnProperty(k)) continue;
+        headers[k] = options[k];
+      }
+    }
 
-  // if the size of this stream is known, plus the total content-length;
-  // otherwise, content-length is unknown.
-  if (typeof size === 'number') {
-    this._knownStreamSize += leading.length;
-    this._knownStreamSize += size;
-    this._knownStreamSize += NEW_LINE_BUFFER.length;
-  } else {
-    this._isAllStreamSizeKnown = false;
+    return headers;
   }
 
-  process.nextTick(this.resume.bind(this));
+  file(name, filepath, filename, filesize) {
+    const mimeType = mime.lookup(filepath);
 
-  return this;
-};
+    if (typeof filename === 'number' && !filesize) {
+      filesize = filename;
+      filename = path.basename(filepath);
+    } else if (!filename) {
+      filename = path.basename(filepath);
+    }
 
-FormStream.prototype.buffer = function (name, buffer, filename, mimeType) {
-  if (filename && !mimeType) {
-    mimeType = mime.lookup(filename);
-  }
+    const stream = fs.createReadStream(filepath);
 
-  var disposition = { name: name };
-  if (filename) {
-    disposition.filename = filename;
+    return this.stream(name, stream, filename, mimeType, filesize);
   }
 
-  var leading = this._leading(disposition, mimeType);
+  stream(name, stream, filename, mimeType, size) {
+    if (typeof mimeType === 'number' && !size) {
+      size = mimeType;
+      mimeType = mime.lookup(filename);
+    } else if (!mimeType) {
+      mimeType = mime.lookup(filename);
+    }
 
-  this._buffers.push([leading, buffer]);
+    if (stream.pause) stream.pause();
 
-  // plus buffer length to total content-length
-  this._contentLength += leading.length;
-  this._contentLength += buffer.length;
-  this._contentLength += NEW_LINE_BUFFER.length;
+    // if form stream destroy, also destroy the source stream
+    stream.once('error', this.emit.bind(this, 'error'));
 
-  process.nextTick(this.resume.bind(this));
+    const leading = this._leading({ name, filename }, mimeType);
+    this._streams.push([ leading, stream ]);
 
-  return this;
-};
+    // if the size of this stream is known, plus the total content-length;
+    // otherwise, content-length is unknown.
+    if (typeof size === 'number') {
+      this._knownStreamSize += leading.length;
+      this._knownStreamSize += size;
+      this._knownStreamSize += NEW_LINE_BUFFER.length;
+    } else {
+      this._isAllStreamSizeKnown = false;
+    }
 
-FormStream.prototype._leading = function (disposition, type) {
-  var leading = [PADDING + this._boundary];
+    return this;
+  }
 
-  var disps = [];
+  pause() {
+    if (this._currentStream && this._currentStream.pause) {
+      this._currentStream.pause();
+    }
+    super.pause();
+  }
 
-  if (disposition) {
-    for (var k in disposition) {
-      disps.push(k + '="' + disposition[k] + '"');
+  resume() {
+    if (this._currentStream && this._currentStream.resume) {
+      this._currentStream.resume();
     }
+    super.resume();
   }
 
-  leading.push('Content-Disposition: form-data; ' + disps.join('; '));
+  buffer(name, buffer, filename, mimeType) {
+    if (filename && !mimeType) {
+      mimeType = mime.lookup(filename);
+    }
 
-  if (type) {
-    leading.push('Content-Type: ' + type);
-  }
+    const disposition = { name: name };
+    if (filename) {
+      disposition.filename = filename;
+    }
 
-  leading.push('');
-  leading.push('');
+    const leading = this._leading(disposition, mimeType);
 
-  return new Buffer(leading.join(NEW_LINE));
-};
+    this._buffers.push([ leading, buffer ]);
 
-FormStream.prototype._emitBuffers = function () {
-  if (!this._buffers.length) {
-    return;
-  }
+    // plus buffer length to total content-length
+    this._contentLength += leading.length;
+    this._contentLength += buffer.length;
+    this._contentLength += NEW_LINE_BUFFER.length;
 
-  for (var i = 0; i < this._buffers.length; i++) {
-    var item = this._buffers[i];
-    this.emit('data', item[0]); // part leading
-    this.emit('data', item[1]); // part content
-    this.emit('data', NEW_LINE_BUFFER);
+    return this;
   }
 
-  this._buffers = [];
-};
-
-FormStream.prototype._emitStream = function (item) {
-  var self = this;
-  // item: [ fieldData, stream ]
-  self.emit('data', item[0]);
-
-  var stream = item[1];
-  stream.on('data', function (data) {
-    self.emit('data', data);
-  });
-  stream.on('end', function () {
-    self.emit('data', NEW_LINE_BUFFER);
-    return process.nextTick(self.drain.bind(self));
-  });
-  stream.resume();
-};
-
-FormStream.prototype._emitEnd = function () {
-  // ending format:
-  //
-  // --{boundary}--\r\n
-  this.emit('data', this._endData);
-  this.emit('end');
-};
-
-FormStream.prototype.drain = function () {
-  this._emitBuffers();
-
-  var item = this._streams.shift();
-  if (item) {
-    this._emitStream(item);
-  } else {
-    this._emitEnd();
-  }
+  _leading(disposition, type) {
+    const leading = [ `${PADDING}${this._boundary}` ];
+
+    const disps = [];
 
-  return this;
-};
+    if (disposition) {
+      for (const k in disposition) {
+        if (!disposition.hasOwnProperty(k)) continue;
+        disps.push(`${k}="${disposition[k]}"`);
+      }
+    }
+
+    leading.push(`Content-Disposition: form-data; ${disps.join('; ')}`);
+
+    if (type) {
+      leading.push(`Content-Type: ${type}`);
+    }
 
-FormStream.prototype.resume = function () {
-  this.paused = false;
+    leading.push('');
+    leading.push('');
 
-  if (!this._draining) {
-    this._draining = true;
-    this.drain();
+    return Buffer.from(leading.join(NEW_LINE));
   }
 
-  return this;
-};
+  field(name, value) {
+    if (!Buffer.isBuffer(value)) {
+      // field(String, Number)
+      // https://github.com/qiniu/nodejs-sdk/issues/123
+      if (typeof value === 'number') {
+        value = value.toString();
+      }
+      value = Buffer.from(value);
+    }
+
+    return this.buffer(name, value);
+  }
 
-FormStream.prototype.close = FormStream.prototype.destroy = function () {
-  this.emit('destroy');
-};
+  _destroy() {
+    for (const stream of this._streams) {
+      stream[1].destroy();
+    }
+    this._streams = [];
+    if (this._currentStream) {
+      this._currentStream.destroy();
+      this._currentStream = null;
+    }
+  }
+}
+
+module.exports = FormStream;
diff --git a/package.json b/package.json
index 16d9d8f..c914562 100644
--- a/package.json
+++ b/package.json
@@ -27,16 +27,15 @@
     "request"
   ],
   "dependencies": {
-    "destroy": "^1.0.4",
-    "mime": "^1.3.4",
-    "pause-stream": "~0.0.11"
+    "debug": "^4.0.1",
+    "mime": "^1.3.4"
   },
   "devDependencies": {
     "autod": "*",
     "connect-multiparty": "1",
     "express": "4",
     "istanbul": "*",
-    "mocha": "*",
+    "mocha": "3",
     "pedding": "1",
     "should": "4",
     "urllib": "2"
diff --git a/test/formstream.test.js b/test/formstream.test.js
index 1d40120..6d17f7a 100644
--- a/test/formstream.test.js
+++ b/test/formstream.test.js
@@ -7,23 +7,25 @@ var fs = require('fs');
 var path = require('path');
 var should = require('should');
 var urllib = require('urllib');
-var formstream = require('../');
+var FormStream = require('../');
 
 var root = path.join(__dirname, 'fixtures');
 var app = require('./fixtures/server');
 
 function cunterStream(name, count) {
-  var s = new Stream();
+  var s = new Stream.Readable({
+    read: () => {}
+  });
   s.size = 0;
   var timer = setInterval(function () {
     var data = name + ' counter stream' + count + '\r\n';
     s.size += data.length;
-    s.emit('data', data);
+    s.push(data);
     count--;
     if (count <= 0) {
       clearInterval(timer);
       process.nextTick(function () {
-        s.emit('end');
+        s.push(null);
       });
     }
   }, 100);
@@ -76,11 +78,11 @@ describe('formstream.test.js', function () {
 
   it('should post fields only with content-length', function (done) {
     done = pedding(2, done);
-    var form = formstream();
+    var form = new FormStream();
     form.field('foo', 'bar');
     form.field('name', '中文名字');
     form.field('pwd', '哈哈pwd');
-    form.on('destroy', done);
+    form.on('end', done);
     post(port, '/post', form, function (err, data) {
       should.not.exist(err);
       data.body.should.eql({
@@ -98,7 +100,7 @@ describe('formstream.test.js', function () {
 
   it.skip('should upload a stream without size, use "Transfer-Encoding: chunked"', function (done) {
     var ChunkedStream = require('../../chunked');
-    var form = formstream();
+    var form = new FormStream();
     form.stream('file', fs.createReadStream(path.join(__dirname, 'fixtures', 'foo.txt')), 'foo.txt');
     form.field('name', '哈哈');
     var headers = form.headers();
@@ -127,13 +129,14 @@ describe('formstream.test.js', function () {
   it('should post fields and file', function (done) {
     done = pedding(2, done);
     var now = Date.now();
-    var form = formstream();
+    var form = new FormStream();
     form.field('foo', 'bar');
     form.field('name', '中文名字');
     form.field('pwd', '哈哈pwd');
     form.field('now', now);
     form.file('file', __filename);
-    form.on('destroy', done);
+    form.on('end', done);
+    form.on('error', console.log);
     post(port, '/post', form, function (err, data) {
       data.body.should.eql({
         foo: 'bar',
@@ -155,7 +158,7 @@ describe('formstream.test.js', function () {
 
   it('should post fields and file with content-length', function (done) {
     fs.stat(__filename, function (err, stat) {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       form.field('name', '中文名字');
       form.field('pwd', '哈哈pwd');
@@ -181,7 +184,7 @@ describe('formstream.test.js', function () {
   });
 
   it('should post fields and file with wrong stream size will return error', function (done) {
-    var form = formstream();
+    var form = new FormStream();
     form.field('foo', 'bar');
     form.field('name', '中文名字');
     form.field('pwd', '哈哈pwd');
@@ -194,7 +197,7 @@ describe('formstream.test.js', function () {
   });
 
   it('should post fields and file with wrong size will return error', function (done) {
-    var form = formstream();
+    var form = new FormStream();
     form.field('foo', 'bar');
     form.field('name', '中文名字');
     form.field('pwd', '哈哈pwd');
@@ -208,7 +211,7 @@ describe('formstream.test.js', function () {
   if (process.version.indexOf('v0.8.') !== 0) {
     // node 0.8, createSteram not exists file will throw error
     it('should post not exist file return error ENOENT', function (done) {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       form.field('name', '中文名字');
       form.field('pwd', '哈哈pwd');
@@ -224,7 +227,7 @@ describe('formstream.test.js', function () {
   }
 
   it('should post fields and stream', function (done) {
-    var form = formstream();
+    var form = new FormStream();
     var s1 = cunterStream('no1', 5);
     form.stream('stream1', s1, 'stream1中文名.txt', 'text/html');
     var s2 = cunterStream('no2', 3);
@@ -263,7 +266,7 @@ describe('formstream.test.js', function () {
   });
 
   it('should post fields, 2 file', function (done) {
-    var form = formstream();
+    var form = new FormStream();
     form.field('foo', 'bar');
     form.field('name', '中文名字');
     form.field('pwd', '哈哈pwd');
@@ -289,7 +292,7 @@ describe('formstream.test.js', function () {
   it('should post fields, 2 file with content-length', function (done) {
     var size = 0;
     var ready = function () {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       form.field('name', '中文名字');
       form.field('pwd', '哈哈pwd');
@@ -327,7 +330,7 @@ describe('formstream.test.js', function () {
 
   describe('buffer()', function () {
     it('should post file content buffer', function (done) {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       form.field('name', '中文名字');
       form.field('pwd', '哈哈pwd');
@@ -364,7 +367,7 @@ describe('formstream.test.js', function () {
     });
 
     it('should post file content buffer with content-length', function (done) {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       form.field('name', '中文名字');
       form.field('pwd', '哈哈pwd');
@@ -397,7 +400,7 @@ describe('formstream.test.js', function () {
 
   describe('headers()', function () {
     it('should get headers contains correct content-length', function () {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar');
       var headers = form.headers({ 'X-Test': 'hello' });
       headers.should.have.keys('Content-Type', 'Content-Length', 'X-Test');
@@ -407,17 +410,17 @@ describe('formstream.test.js', function () {
     });
 
     it('should trust .setTotalStreamSize() only if has any stream/file without size specified', function () {
-      var headers1 = formstream()
+      var headers1 = new FormStream()
         .field('field', 'plain')
-        .file('file', './logo.png', 'file')
+        .file('file', './test/fixtures/logo.png', 'file')
         .buffer('buffer', new Buffer(20), 'buffer')
         .stream('stream', cunterStream('stream', 5), 'stream')
         .setTotalStreamSize(10)
         .headers();
 
-      var headers2 = formstream()
+      var headers2 = new FormStream()
         .field('field', 'plain')
-        .file('file', './logo.png', 'file', 10)
+        .file('file', './test/fixtures/logo.png', 'file', 10)
         .buffer('buffer', new Buffer(20), 'buffer')
         .stream('stream', cunterStream('stream', 5), 'stream', 30)
         .headers();
@@ -434,27 +437,27 @@ describe('formstream.test.js', function () {
 
   describe('chaining', function () {
     it('should do chaining calls with .field()', function () {
-      var form = formstream();
+      var form = new FormStream();
       form.field('foo', 'bar').should.equal(form);
     });
 
     it('should do chaining calls with .file()', function () {
-      var form = formstream();
-      form.file('foo', './logo.png', 'bar').should.equal(form);
+      var form = new FormStream();
+      form.file('foo', './test/fixtures/logo.png', 'bar').should.equal(form);
     });
 
     it('should do chaining calls with .buffer()', function () {
-      var form = formstream();
+      var form = new FormStream();
       form.buffer('foo', new Buffer('foo content'), 'bar').should.equal(form);
     });
 
     it('should do chaining calls with .stream()', function () {
-      var form = formstream();
+      var form = new FormStream();
       form.stream('foo', cunterStream('stream', 5), 'bar').should.equal(form);
     });
 
     it('should do chaining calls with .setTotalStreamSize()', function () {
-      var form = formstream();
+      var form = new FormStream();
       form.setTotalStreamSize(10).should.equal(form);
     });
   });