diff --git a/lib/packer.js b/lib/packer.js
index d0336b1..325c83d 100755
--- a/lib/packer.js
+++ b/lib/packer.js
@@ -23,12 +23,16 @@ var Packer = module.exports = function(options) {
 util.inherits(Packer, Stream);
 
 
-Packer.prototype.pack = function(data, width, height) {
+Packer.prototype.pack = function(data, width, height, gamma) {
 
   // Signature
   this.emit('data', new Buffer(constants.PNG_SIGNATURE));
   this.emit('data', this._packIHDR(width, height));
 
+  if (gamma) {
+    this.emit('data', this._packGAMA(gamma));
+  }
+
   // filter pixel data
   //TODO {}
   var filter = new Filter(width, height, 4, 8, false, this._options, {});
@@ -70,6 +74,12 @@ Packer.prototype._packChunk = function(type, data) {
   return buf;
 };
 
+Packer.prototype._packGAMA = function(gamma) {
+  var buf = new Buffer(4);
+  buf.writeUInt32BE(Math.floor(gamma * 100000), 0); // TODO constant
+  return this._packChunk(constants.TYPE_gAMA, buf);
+};
+
 Packer.prototype._packIHDR = function(width, height) {
 
   var buf = new Buffer(13);
diff --git a/lib/parser.js b/lib/parser.js
index b2730f5..500f05f 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -249,7 +249,7 @@ Parser.prototype._handleGAMA = function(length) {
 Parser.prototype._parseGAMA = function(data) {
 
   this._crc.write(data);
-  this.gamma(data.readUInt32BE(0) / 100000);
+  this.gamma(data.readUInt32BE(0) / 100000); //TODO constant
 
   this._handleChunkEnd();
 };
diff --git a/lib/png.js b/lib/png.js
index 65cd6a0..eedc535 100755
--- a/lib/png.js
+++ b/lib/png.js
@@ -55,7 +55,7 @@ PNG.prototype.pack = function() {
   }
 
   process.nextTick(function() {
-    this._packer.pack(this.data, this.width, this.height);
+    this._packer.pack(this.data, this.width, this.height, this.gamma);
   }.bind(this));
 
   return this;
diff --git a/package.json b/package.json
index 665b8ee..a1f5ec6 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "pngjs2",
   "version": "0.0.3",
-  "description": "Pure JS PNG encoder/decoder",
+  "description": "PNG encoder/decoder in pure JS, supporting any bit size & interlace, async & sync with full test suite.",
   "contributors": [
     "Alexandre Paré",
     "Gaurav Mali",
diff --git a/test/convert-images.js b/test/convert-images.js
index f2b23be..8ae5fde 100644
--- a/test/convert-images.js
+++ b/test/convert-images.js
@@ -57,7 +57,7 @@ module.exports = function(done) {
                 } else {
 
                     var outpng = new PNG();
-                    //PNG.adjustGamma(png);
+                    outpng.gamma = png.gamma;
                     outpng.data = png.data;
                     outpng.width = png.width;
                     outpng.height = png.height;
@@ -82,7 +82,6 @@ module.exports = function(done) {
                   if (expectedError) {
                       console.log("Async: Error expected, parsed fine ..", file);
                   }
-                  //this.adjustGamma();
 
                   this.pack()
                   .pipe(