diff --git a/README.md b/README.md
index 6b97fe5..2a8baa5 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,7 @@ Google it.
     -A, --amount <connections>      the amount of persistent connections to generate
     -C, --concurrent <connections>  how many concurrent-connections per second
     -M, --messages <messages>       messages to be send per connection
+    -H, --header [header]           a header to pass to each connection
     -P, --protocol <protocol>       WebSocket protocol version
     -B, --buffer <size>             size of the messages that are send
     -W, --workers <cpus>            workers to be spawned
diff --git a/bin/thor b/bin/thor
index 9db08f2..564b046 100755
--- a/bin/thor
+++ b/bin/thor
@@ -7,6 +7,14 @@ var Metrics = require('../metrics')
   , path = require('path')
   , os = require('os');
 
+function collect(val, memo) {
+  if(!memo){
+    memo = [];
+  }
+  memo.push(val);
+  return memo;
+}
+
 //
 // Setup the Command-Line Interface.
 //
@@ -16,6 +24,7 @@ cli.usage('[options] ws://localhost')
    .option('-A, --amount <connections>', 'the amount of persistent connections to generate', parseInt, 10000)
    .option('-C, --concurrent <connections>', 'how many concurrent-connections per second', parseInt, 0)
    .option('-M, --messages <messages>', 'messages to be send per connection', parseInt, 1)
+   .option('-H, --header [header]', 'a header to pass to each connection', collect, [])
    .option('-P, --protocol <protocol>', 'WebSocket protocol version', parseInt, 13)
    .option('-B, --buffer <size>', 'size of the messages that are send', parseInt, 1024)
    .option('-W, --workers <cpus>', 'workers to be spawned', parseInt, os.cpus().length)
@@ -47,6 +56,22 @@ var cluster = require('cluster')
   , received = 0
   , robin = [];
 
+//
+// Process headers
+//
+var headers = {};
+cli.header.forEach(function(header){
+  var keyValue = header.split(':');
+  var key = keyValue[0];
+  var value = keyValue[1];
+  if(!key || !value){
+    console.warn('Header \'' +  + '\' is wrongly defined. A header should looks like \'key:value\'.');
+    return;
+  }
+  headers[key.trim()] = value.trim();
+});
+console.log(headers);
+
 cluster.setupMaster({
     exec: path.resolve(__dirname, '../mjolnir.js')
   , silent: false
@@ -56,7 +81,8 @@ cluster.setupMaster({
       : path.resolve(__dirname, '../generator.js'),
       cli.protocol,
       !!cli.masked,
-      !!cli.binary
+      !!cli.binary,
+      headers
     ]
 });
 
diff --git a/mjolnir.js b/mjolnir.js
index c22f517..5ac4a2d 100644
--- a/mjolnir.js
+++ b/mjolnir.js
@@ -14,7 +14,8 @@ var session = require(process.argv[2]);
 //
 var masked = process.argv[4] === 'true'
   , binary = process.argv[5] === 'true'
-  , protocol = +process.argv[3] || 13;
+  , protocol = +process.argv[3] || 13
+  , headers = process.argv[6];
 
 process.on('message', function message(task) {
   var now = Date.now();
@@ -41,7 +42,8 @@ process.on('message', function message(task) {
   if (!task.url) return;
 
   var socket = new Socket(task.url, {
-    protocolVersion: protocol
+    protocolVersion: protocol,
+    headers: headers
   });
 
   socket.on('open', function open() {
diff --git a/package.json b/package.json
index bdfe97b..26ef0aa 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
   "author": "Arnout Kazemier <opensource@observe.it>",
   "license": "MIT",
   "dependencies": {
-    "commander": "1.1.x",
+    "commander": "2.9.0",
     "async": "0.2.x",
     "tab": "0.1.x",
     "colors": "0.6.x",