diff --git a/dist/riff-chunks-min.js b/dist/riff-chunks-min.js
index 0f10d80..3dfe544 100644
--- a/dist/riff-chunks-min.js
+++ b/dist/riff-chunks-min.js
@@ -1,13 +1,13 @@
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+};c.prototype.v=function(){8<this.b&&(this.h=(this.b-1|7)+1)};c.prototype.s=function(){var a=8-(this.h-this.b);this.i=Math.pow(2,0<a?a:8)-1};c.prototype.B=function(a,c,f){8>this.b?a[f++]=0>c?c+Math.pow(2,this.b):c:a[f++]=c&255;return f};a.a=c}]);
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diff --git a/docs/global.html b/docs/global.html
index 50d8ce9..886905f 100644
--- a/docs/global.html
+++ b/docs/global.html
@@ -115,7 +115,7 @@ <h3 class="subsection-title">Methods</h3>
 
     
 
-    <h4 class="name" id="read"><span class="type-signature"></span>read<span class="signature">(buffer)</span><span class="type-signature"> &rarr; {Object}</span></h4>
+    <h4 class="name" id="read"><span class="type-signature"></span>read<span class="signature">(buffer)</span><span class="type-signature"> &rarr; (non-null) {Object}</span></h4>
 
     
 
@@ -127,7 +127,7 @@ <h4 class="name" id="read"><span class="type-signature"></span>read<span class="
     
     <dt class="tag-source">Source:</dt>
     <dd class="tag-source"><ul class="dummy"><li>
-        <a href="index.js.html">index.js</a>, <a href="index.js.html#line40">line 40</a>
+        <a href="index.js.html">index.js</a>, <a href="index.js.html#line41">line 41</a>
     </li></ul></dd>
     
 
@@ -214,7 +214,7 @@ <h5>Parameters:</h5>
 <span class="param-type">Uint8Array</span>
 |
 
-<span class="param-type">Array.&lt;number></span>
+<span class="param-type">!Array.&lt;number></span>
 
 
             
@@ -273,7 +273,7 @@ <h5>Returns:</h5>
 
     
 
-    <h4 class="name" id="write"><span class="type-signature"></span>write<span class="signature">(chunks)</span><span class="type-signature"> &rarr; {Uint8Array}</span></h4>
+    <h4 class="name" id="write"><span class="type-signature"></span>write<span class="signature">(chunks<span class="signature-attributes">non-null</span>)</span><span class="type-signature"> &rarr; {!Array.&lt;number>|Uint8Array}</span></h4>
 
     
 
@@ -285,7 +285,7 @@ <h4 class="name" id="write"><span class="type-signature"></span>write<span class
     
     <dt class="tag-source">Source:</dt>
     <dd class="tag-source"><ul class="dummy"><li>
-        <a href="index.js.html">index.js</a>, <a href="index.js.html#line21">line 21</a>
+        <a href="index.js.html">index.js</a>, <a href="index.js.html#line22">line 22</a>
     </li></ul></dd>
     
 
@@ -403,7 +403,7 @@ <h5>Returns:</h5>
 
         
 <div class="param-desc">
-    The file bytes as Uint8Array when
     chunkId is "RIFF" or "RIFX" or the chunk bytes as Array<number>
     when chunkId is "LIST".
+    The bytes as Uint8Array when chunkId is
     "RIFF" or "RIFX" or the chunk bytes as Array<number> when chunkId is "LIST".
 </div>
 
 
@@ -414,6 +414,9 @@ <h5>Returns:</h5>
     </dt>
     <dd>
         
+<span class="param-type">!Array.&lt;number></span>
+|
+
 <span class="param-type">Uint8Array</span>
 
 
@@ -441,7 +444,7 @@ <h5>Returns:</h5>
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Thu May 03 2018 23:19:51 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Sat May 05 2018 21:25:48 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
 </footer>
 
 <script>prettyPrint();</script>
diff --git a/docs/index.html b/docs/index.html
index a6bdff4..94ffc51 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -105,7 +105,7 @@ <h2>riffChunks.write()</h2><pre class="prettyprint source lang-javascript"><code
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Thu May 03 2018 23:19:51 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Sat May 05 2018 21:25:48 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
 </footer>
 
 <script>prettyPrint();</script>
diff --git a/docs/index.js.html b/docs/index.js.html
index 311ca6f..8ddd0f5 100644
--- a/docs/index.js.html
+++ b/docs/index.js.html
@@ -48,24 +48,25 @@ <h1 class="page-title">index.js</h1>
 /** @private */
 const byteData = require("byte-data");
 /** @private */
-let uInt32 = byteData.uInt32;
+const uInt32_ = {"bits": 32};
+/** @private */
+const fourCC_ = {"bits": 32, "char": true};
 
 /**
  * Write the bytes of a RIFF/RIFX file.
- * @param {Object} chunks A structure like the return of riffChunks.read().
- * @return {Uint8Array} The file bytes as Uint8Array when
- *      chunkId is "RIFF" or "RIFX" or the chunk bytes as Array&lt;number>
- *      when chunkId is "LIST".
+ * @param {!Object} chunks A structure like the return of riffChunks.read().
+ * @return {!Array&lt;number>|Uint8Array} The bytes as Uint8Array when chunkId is
+ *      "RIFF" or "RIFX" or the chunk bytes as Array&lt;number> when chunkId is "LIST".
  */
 function write(chunks) {
-    uInt32["be"] = chunks["chunkId"] === "RIFX";
+    uInt32_["be"] = chunks["chunkId"] == "RIFX";
     let bytes =
-        byteData.packArray(chunks["chunkId"], byteData.chr).concat(
-                byteData.pack(chunks["chunkSize"], uInt32),
-                byteData.packArray(chunks["format"], byteData.chr),
+        byteData.pack(chunks["chunkId"], fourCC_).concat(
+                byteData.pack(chunks["chunkSize"], uInt32_),
+                byteData.pack(chunks["format"], fourCC_),
                 writeSubChunks_(chunks["subChunks"])
             );
-    if (chunks["chunkId"] === "RIFF" || chunks["chunkId"] === "RIFX" ) {
+    if (chunks["chunkId"] == "RIFF" || chunks["chunkId"] == "RIFX" ) {
         bytes = new Uint8Array(bytes);
     }
     return bytes;
@@ -73,37 +74,37 @@ <h1 class="page-title">index.js</h1>
 
 /**
  * Get the chunks of a RIFF/RIFX file.
- * @param {Uint8Array|Array&lt;number>} buffer The file bytes.
- * @return {Object} The chunk.
+ * @param {!Uint8Array|!Array&lt;number>} buffer The file bytes.
+ * @return {!Object} The chunk.
  */
 function read(buffer) {
     buffer = [].slice.call(buffer);
     let chunkId = getChunkId_(buffer, 0);
-    uInt32["be"] = chunkId === "RIFX";
+    uInt32_["be"] = chunkId == "RIFX";
     return {
         "chunkId": chunkId,
         "chunkSize": getChunkSize_(buffer, 0),
-        "format": byteData.unpackArray(buffer.slice(8, 12), byteData.chr),
+        "format": byteData.unpack(buffer.slice(8, 12), fourCC_),
         "subChunks": getSubChunks_(buffer)
     };
 }
 
 /**
  * Write the sub chunks of a RIFF file.
- * @param {Array&lt;Object>} chunks The chunks.
- * @return {Array&lt;number>} The chunk bytes.
+ * @param {!Array&lt;!Object>} chunks The chunks.
+ * @return {!Array&lt;number>} The chunk bytes.
  * @private
  */
 function writeSubChunks_(chunks) {
     let subChunks = [];
     let i = 0;
     while (i &lt; chunks.length) {
-        if (chunks[i]["chunkId"] === "LIST") {
+        if (chunks[i]["chunkId"] == "LIST") {
             subChunks = subChunks.concat(write(chunks[i]));
         } else {
             subChunks = subChunks.concat(
-                byteData.packArray(chunks[i]["chunkId"], byteData.chr),
-                byteData.pack(chunks[i]["chunkSize"], uInt32),
+                byteData.pack(chunks[i]["chunkId"], fourCC_),
+                byteData.pack(chunks[i]["chunkSize"], uInt32_),
                 chunks[i]["chunkData"]
             );
         }
@@ -114,8 +115,8 @@ <h1 class="page-title">index.js</h1>
 
 /**
  * Get the sub chunks of a RIFF file.
- * @param {Uint8Array|Array&lt;number>} buffer the RIFF file bytes.
- * @return {Object} The subchunks of a RIFF/RIFX or LIST chunk.
+ * @param {!Uint8Array|!Array&lt;number>} buffer the RIFF file bytes.
+ * @return {!Array&lt;Object>} The subchunks of a RIFF/RIFX or LIST chunk.
  * @private
  */
 function getSubChunks_(buffer) {
@@ -130,18 +131,20 @@ <h1 class="page-title">index.js</h1>
 
 /**
  * Get a sub chunk from a RIFF file.
- * @param {Uint8Array|Array&lt;number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {Object} A subchunk of a RIFF/RIFX or LIST chunk.
+ * @param {!Uint8Array|!Array&lt;number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
  * @private
  */
 function getSubChunk_(buffer, index) {
     let chunk = {
         "chunkId": getChunkId_(buffer, index),
-        "chunkSize": getChunkSize_(buffer, index)
+        "chunkSize": getChunkSize_(buffer, index),
+        "subChunks": [],
+        "chunkData": []
     };
-    if (chunk["chunkId"] === "LIST") {
-        chunk["format"] = byteData.unpackArray(buffer.slice(8, 12), byteData.chr);
+    if (chunk["chunkId"] == "LIST") {
+        chunk["format"] = byteData.unpack(buffer.slice(8, 12), fourCC_);
         chunk["subChunks"] = getSubChunks_(
             buffer.slice(index, index + chunk["chunkSize"]));
     } else {
@@ -152,25 +155,25 @@ <h1 class="page-title">index.js</h1>
 }
 
 /**
- * Return the FourCC of a chunk.
- * @param {Uint8Array|Array&lt;number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {string} The id of the chunk.
+ * Return the fourCC_ of a chunk.
+ * @param {!Uint8Array|!Array&lt;number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!string} The id of the chunk.
  * @private
  */
 function getChunkId_(buffer, index) {
-    return byteData.unpackArray(buffer.slice(index, index + 4), byteData.chr);
+    return byteData.unpack(buffer.slice(index, index + 4), fourCC_);
 }
 
 /**
  * Return the size of a chunk.
- * @param {Uint8Array|Array&lt;number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {number} The size of the chunk without the id and size fields.
+ * @param {!Uint8Array|!Array&lt;number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!number} The size of the chunk without the id and size fields.
  * @private
  */
 function getChunkSize_(buffer, index) {
-    return byteData.unpack(buffer.slice(index + 4, index + 8), uInt32);
+    return byteData.unpack(buffer.slice(index + 4, index + 8), uInt32_);
 }
 
 module.exports.read = read;
@@ -187,7 +190,7 @@ <h1 class="page-title">index.js</h1>
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Thu May 03 2018 23:19:51 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.5.5</a> on Sat May 05 2018 21:25:48 GMT-0300 (Hora oficial do Brasil) using the <a href="https://github.com/clenemt/docdash">docdash</a> theme.
 </footer>
 
 <script>prettyPrint();</script>
diff --git a/index.js b/index.js
index 4686056..adc6bc6 100644
--- a/index.js
+++ b/index.js
@@ -9,24 +9,25 @@
 /** @private */
 const byteData = require("byte-data");
 /** @private */
-let uInt32 = byteData.uInt32;
+const uInt32_ = {"bits": 32};
+/** @private */
+const fourCC_ = {"bits": 32, "char": true};
 
 /**
  * Write the bytes of a RIFF/RIFX file.
- * @param {Object} chunks A structure like the return of riffChunks.read().
- * @return {Uint8Array} The file bytes as Uint8Array when
- *      chunkId is "RIFF" or "RIFX" or the chunk bytes as Array<number>
- *      when chunkId is "LIST".
+ * @param {!Object} chunks A structure like the return of riffChunks.read().
+ * @return {!Array<number>|Uint8Array} The bytes as Uint8Array when chunkId is
+ *      "RIFF" or "RIFX" or the chunk bytes as Array<number> when chunkId is "LIST".
  */
 function write(chunks) {
-    uInt32["be"] = chunks["chunkId"] === "RIFX";
+    uInt32_["be"] = chunks["chunkId"] == "RIFX";
     let bytes =
-        byteData.packArray(chunks["chunkId"], byteData.chr).concat(
-                byteData.pack(chunks["chunkSize"], uInt32),
-                byteData.packArray(chunks["format"], byteData.chr),
+        byteData.pack(chunks["chunkId"], fourCC_).concat(
+                byteData.pack(chunks["chunkSize"], uInt32_),
+                byteData.pack(chunks["format"], fourCC_),
                 writeSubChunks_(chunks["subChunks"])
             );
-    if (chunks["chunkId"] === "RIFF" || chunks["chunkId"] === "RIFX" ) {
+    if (chunks["chunkId"] == "RIFF" || chunks["chunkId"] == "RIFX" ) {
         bytes = new Uint8Array(bytes);
     }
     return bytes;
@@ -34,37 +35,37 @@ function write(chunks) {
 
 /**
  * Get the chunks of a RIFF/RIFX file.
- * @param {Uint8Array|Array<number>} buffer The file bytes.
- * @return {Object} The chunk.
+ * @param {!Uint8Array|!Array<number>} buffer The file bytes.
+ * @return {!Object} The chunk.
  */
 function read(buffer) {
     buffer = [].slice.call(buffer);
     let chunkId = getChunkId_(buffer, 0);
-    uInt32["be"] = chunkId === "RIFX";
+    uInt32_["be"] = chunkId == "RIFX";
     return {
         "chunkId": chunkId,
         "chunkSize": getChunkSize_(buffer, 0),
-        "format": byteData.unpackArray(buffer.slice(8, 12), byteData.chr),
+        "format": byteData.unpack(buffer.slice(8, 12), fourCC_),
         "subChunks": getSubChunks_(buffer)
     };
 }
 
 /**
  * Write the sub chunks of a RIFF file.
- * @param {Array<Object>} chunks The chunks.
- * @return {Array<number>} The chunk bytes.
+ * @param {!Array<!Object>} chunks The chunks.
+ * @return {!Array<number>} The chunk bytes.
  * @private
  */
 function writeSubChunks_(chunks) {
     let subChunks = [];
     let i = 0;
     while (i < chunks.length) {
-        if (chunks[i]["chunkId"] === "LIST") {
+        if (chunks[i]["chunkId"] == "LIST") {
             subChunks = subChunks.concat(write(chunks[i]));
         } else {
             subChunks = subChunks.concat(
-                byteData.packArray(chunks[i]["chunkId"], byteData.chr),
-                byteData.pack(chunks[i]["chunkSize"], uInt32),
+                byteData.pack(chunks[i]["chunkId"], fourCC_),
+                byteData.pack(chunks[i]["chunkSize"], uInt32_),
                 chunks[i]["chunkData"]
             );
         }
@@ -75,8 +76,8 @@ function writeSubChunks_(chunks) {
 
 /**
  * Get the sub chunks of a RIFF file.
- * @param {Uint8Array|Array<number>} buffer the RIFF file bytes.
- * @return {Object} The subchunks of a RIFF/RIFX or LIST chunk.
+ * @param {!Uint8Array|!Array<number>} buffer the RIFF file bytes.
+ * @return {!Array<Object>} The subchunks of a RIFF/RIFX or LIST chunk.
  * @private
  */
 function getSubChunks_(buffer) {
@@ -91,18 +92,20 @@ function getSubChunks_(buffer) {
 
 /**
  * Get a sub chunk from a RIFF file.
- * @param {Uint8Array|Array<number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {Object} A subchunk of a RIFF/RIFX or LIST chunk.
+ * @param {!Uint8Array|!Array<number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!Object} A subchunk of a RIFF/RIFX or LIST chunk.
  * @private
  */
 function getSubChunk_(buffer, index) {
     let chunk = {
         "chunkId": getChunkId_(buffer, index),
-        "chunkSize": getChunkSize_(buffer, index)
+        "chunkSize": getChunkSize_(buffer, index),
+        "subChunks": [],
+        "chunkData": []
     };
-    if (chunk["chunkId"] === "LIST") {
-        chunk["format"] = byteData.unpackArray(buffer.slice(8, 12), byteData.chr);
+    if (chunk["chunkId"] == "LIST") {
+        chunk["format"] = byteData.unpack(buffer.slice(8, 12), fourCC_);
         chunk["subChunks"] = getSubChunks_(
             buffer.slice(index, index + chunk["chunkSize"]));
     } else {
@@ -113,25 +116,25 @@ function getSubChunk_(buffer, index) {
 }
 
 /**
- * Return the FourCC of a chunk.
- * @param {Uint8Array|Array<number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {string} The id of the chunk.
+ * Return the fourCC_ of a chunk.
+ * @param {!Uint8Array|!Array<number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!string} The id of the chunk.
  * @private
  */
 function getChunkId_(buffer, index) {
-    return byteData.unpackArray(buffer.slice(index, index + 4), byteData.chr);
+    return byteData.unpack(buffer.slice(index, index + 4), fourCC_);
 }
 
 /**
  * Return the size of a chunk.
- * @param {Uint8Array|Array<number>} buffer the RIFF file bytes.
- * @param {number} index The start index of the chunk.
- * @return {number} The size of the chunk without the id and size fields.
+ * @param {!Uint8Array|!Array<number>} buffer the RIFF file bytes.
+ * @param {!number} index The start index of the chunk.
+ * @return {!number} The size of the chunk without the id and size fields.
  * @private
  */
 function getChunkSize_(buffer, index) {
-    return byteData.unpack(buffer.slice(index + 4, index + 8), uInt32);
+    return byteData.unpack(buffer.slice(index + 4, index + 8), uInt32_);
 }
 
 module.exports.read = read;
diff --git a/package.json b/package.json
index 03b9849..76d2707 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "riff-chunks",
-  "version": "4.0.1",
+  "version": "4.0.2",
   "description": "Read and write the chunks of RIFF and RIFX files.",
   "homepage": "https://github.com/rochars/riff-chunks",
   "author": "Rafael da Silva Rocha <rocha.rafaelsilva@gmail.com>",
@@ -45,6 +45,6 @@
   },
   "main": "index.js",
   "dependencies": {
-    "byte-data": "^7.0.0"
+    "byte-data": "^8.0.0"
   }
 }