diff --git a/fetch.js b/fetch.js
index c54b4814d12868de3ecb991531a3c4b716811ff7..e5284a7e44757b1525c15f8d6f585a175289e56a 100644
--- a/fetch.js
+++ b/fetch.js
@@ -69,56 +69,79 @@
     body.bodyUsed = true
   }
 
+  var blobSupport = self.FileReader && (function() {
+    try {
+      new Blob();
+      return true
+    } catch(e) {
+      return false
+    }
+  })();
+
   function Body() {
     this._body = null
     this.bodyUsed = false
 
-    this.arrayBuffer = function() {
-      throw new Error('Not implemented yet')
-    }
+    if (blobSupport) {
+      this.arrayBuffer = function() {
+        var rejected = consumed(this)
+        if (rejected) {
+          return rejected
+        }
 
-    var blobSupport = (function() {
-      try {
-        new Blob();
-        return true
-      } catch(e) {
-        return false
+        var body = this._body
+        return new Promise(function(resolve, reject) {
+          var fileReader = new FileReader()
+          fileReader.readAsArrayBuffer(body)
+          fileReader.onloadend = function(e) {
+            if (e.target.error) {
+              reject(e.target.error)
+            } else {
+              resolve(e.target.result)
+            }
+          }
+        })
       }
-    })();
 
-    if (blobSupport) {
       this.blob = function() {
         var rejected = consumed(this)
-        return rejected ? rejected : Promise.resolve(new Blob([this._body]))
+        return rejected ? rejected : Promise.resolve(this._body)
       }
-    }
 
-    if (self.FormData) {
-      this.formData = function() {
+      this.text = function() {
+        var rejected = consumed(this)
+        if (rejected) {
+          return rejected
+        }
+
+        var body = this._body
+        return new Promise(function(resolve, reject) {
+          var fileReader = new FileReader()
+          fileReader.readAsText(body)
+          fileReader.onloadend = function(e) {
+            if (e.target.error) {
+              reject(e.target.error)
+            } else {
+              resolve(e.target.result)
+            }
+          }
+        })
+      }
+    } else {
+      this.text = function() {
         var rejected = consumed(this)
-        return rejected ? rejected : Promise.resolve(decode(this._body))
+        return rejected ? rejected : Promise.resolve(this._body)
       }
     }
 
-    this.json = function() {
-      var rejected = consumed(this)
-      if (rejected) {
-        return rejected
+    if (self.FormData) {
+      this.formData = function() {
+        return this.text().then(function(text) { return decode(text) })
       }
-
-      var body = this._body
-      return new Promise(function(resolve, reject) {
-        try {
-          resolve(JSON.parse(body))
-        } catch (ex) {
-          reject(ex)
-        }
-      })
     }
 
-    this.text = function() {
-      var rejected = consumed(this)
-      return rejected ? rejected : Promise.resolve(this._body)
+    this.json = function() {
+      return this.text().then(function(text) { return JSON.parse(text) })
     }
 
     return this
@@ -186,7 +209,7 @@
           headers: headers(xhr),
           url: xhr.responseURL || xhr.getResponseHeader('X-Request-URL')
         }
-        resolve(new Response(xhr.responseText, options))
+        resolve(new Response(blobSupport ? xhr.response: xhr.responseText, options))
       }
 
       xhr.onerror = function() {
@@ -194,6 +217,9 @@
       }
 
       xhr.open(self.method, self.url)
+      if (blobSupport) {
+        xhr.responseType = 'blob'
+      }
 
       self.headers.forEach(function(name, values) {
         values.forEach(function(value) {
diff --git a/test/server.js b/test/server.js
index afc091b15a0e11746922c8cffc5d96c885a1ed80..489fee456023e3cd20db1113aa7677aa0a3186b8 100755
--- a/test/server.js
+++ b/test/server.js
@@ -28,6 +28,14 @@ var routes = {
     });
     res.end('hi');
   },
+  '/nonascii': function(res) {
+    res.writeHead(200, {'Content-Type': 'text/plain'});
+    var buf = new Buffer(256);
+    for (var i = 0; i< 256; i++) {
+      buf[i] = i;
+    }
+    res.end(buf);
+  },
   '/redirect/301': function(res) {
     res.writeHead(301, {'Location': '/hello'});
     res.end();
diff --git a/test/test.js b/test/test.js
index dacf7cc690d1518f5fd878441115bcf213c13602..df649ec27f92629faf414f3bb5f28375f6b84b0e 100644
--- a/test/test.js
+++ b/test/test.js
@@ -63,6 +63,40 @@ suite('Response', function() {
 
 // https://fetch.spec.whatwg.org/#body-mixin
 suite('Body mixin', function() {
+  ;(Response.prototype.arrayBuffer ? suite : suite.skip)('arrayBuffer', function() {
+    test('resolves arrayBuffer promise', function() {
+      return fetch('/hello').then(function(response) {
+        return response.arrayBuffer()
+      }).then(function(buf) {
+        assert(buf instanceof ArrayBuffer, 'buf is an ArrayBuffer instance')
+        assert.equal(buf.byteLength, 2)
+      })
+    })
+
+    test('arrayBuffer handles non-ascii data', function() {
+      return fetch('/nonascii').then(function(response) {
+        return response.arrayBuffer()
+      }).then(function(buf) {
+        assert(buf instanceof ArrayBuffer, 'buf is an ArrayBuffer instance')
+        assert.equal(buf.byteLength, 256, 'buf.byteLength is correct')
+        var view = new Uint8Array(buf)
+        for (var i = 0; i< 256; i++) {
+          assert.equal(view[i], i)
+        }
+      })
+    })
+
+    test('rejects arrayBuffer promise after body is consumed', function() {
+      return fetch('/hello').then(function(response) {
+        assert(response.arrayBuffer, 'Body does not implement arrayBuffer')
+        response.blob()
+        return response.arrayBuffer()
+      }).catch(function(error) {
+        assert(error instanceof TypeError, 'Promise rejected after body consumed')
+      })
+    })
+  })
+
   ;(Response.prototype.blob ? suite : suite.skip)('blob', function() {
     test('resolves blob promise', function() {
       return fetch('/hello').then(function(response) {
@@ -73,6 +107,15 @@ suite('Body mixin', function() {
       })
     })
 
+    test('blob handles non-ascii data', function() {
+      return fetch('/nonascii').then(function(response) {
+        return response.blob()
+      }).then(function(blob) {
+        assert(blob instanceof Blob, 'blob is a Blob instance')
+        assert.equal(blob.size, 256, 'blob.size is correct')
+      })
+    })
+
     test('rejects blob promise after body is consumed', function() {
       return fetch('/hello').then(function(response) {
         assert(response.blob, 'Body does not implement blob')