diff --git a/Gruntfile.js b/Gruntfile.js
index f51c59d..883e953 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -52,6 +52,9 @@ module.exports = function(grunt) {
       custom_cmd: {
         src: 'test/custom_cmd_test.js'
       },
+      custom_harmony: {
+        src: 'test/custom_harmony.js'
+      },
       custom_args: {
         src: 'test/custom_args_test.js'
       },
@@ -90,6 +93,12 @@ module.exports = function(grunt) {
           script: './test/server_malformed.js'
         }
       },
+      custom_harmony: {
+        options: {
+          harmony: true,
+          output: "Express server listening on port .+"
+        }
+      },
       custom_args: {
         options: {
           args: [1, 2],
@@ -153,37 +162,40 @@ module.exports = function(grunt) {
   grunt.registerTask('test', [
     'clean',
     'nodeunit:defaults',
-    'express:defaults',                 
+    'express:defaults',
     'express:defaults:stop',
     'express:malformed',
-    'express:custom_cmd',       
-    'nodeunit:custom_cmd',      
+    'express:custom_cmd',
+    'nodeunit:custom_cmd',
     'express:custom_cmd:stop',
-    'express:custom_args',      
-    'nodeunit:custom_args',     
+    'express:custom_args',
+    'nodeunit:custom_args',
     'express:custom_args:stop',
-    'express:custom_port',      
-    'nodeunit:custom_port',     
+    'express:custom_harmony',
+    'nodeunit:custom_harmony',
+    'express:custom_harmony:stop',
+    'express:custom_port',
+    'nodeunit:custom_port',
     'express:custom_port:stop',
-    'express:custom_node_env',  
-    'nodeunit:custom_node_env', 
+    'express:custom_node_env',
+    'nodeunit:custom_node_env',
     'express:custom_node_env:stop',
-    'express:custom_delay',     
-    'nodeunit:custom_delay',    
+    'express:custom_delay',
+    'nodeunit:custom_delay',
     'express:custom_delay:stop',
-    'express:custom_output',    
-    'nodeunit:custom_output',   
+    'express:custom_output',
+    'nodeunit:custom_output',
     'express:custom_output:stop',
-    'express:stoppable',        
-    'express:stoppable:stop',   
+    'express:stoppable',
+    'express:stoppable:stop',
     'nodeunit:stoppable',
 
     // Multiple servers
-    'express:custom_port',      
-    'nodeunit:defaults', 
-    'express:defaults',       
+    'express:custom_port',
+    'nodeunit:defaults',
+    'express:defaults',
     'nodeunit:custom_port',
-    'express:custom_port:stop', 
+    'express:custom_port:stop',
     'express:defaults:stop',
   ]);
 
diff --git a/tasks/express.js b/tasks/express.js
index 4b601b7..41aca90 100644
--- a/tasks/express.js
+++ b/tasks/express.js
@@ -26,6 +26,7 @@ module.exports = function(grunt) {
       opts:             [ ],
       args:             [ ],
       node_env:         undefined,
+      harmony:          false,
       background:       true,
       fallback:         function() { /* Prevent EADDRINUSE from breaking Grunt */ },
       port:             process.env.PORT || 3000,
@@ -40,6 +41,10 @@ module.exports = function(grunt) {
 
     options.args.unshift(options.script);
 
+    if (options.harmony) {
+      options.args.unshift('--harmony');
+    }
+
     if (!grunt.file.exists(options.script)) {
       grunt.log.error('Could not find server script: ' + options.script);
 
diff --git a/test/app.js b/test/app.js
index fea7271..de1e392 100644
--- a/test/app.js
+++ b/test/app.js
@@ -13,6 +13,10 @@ app.get('/env', function(req, res) {
   res.send('Howdy from ' + app.get('env') + '!');
 });
 
+app.get('/harmony', function(req, res) {
+  res.send('Harmony flag idx is ' + process.execArgv.indexOf('--harmony'));
+});
+
 // Setup simple echo for each additional argument passed for testing
 args.slice(2).forEach(function(arg) {
   app.get('/' + arg, function(req, res) {
diff --git a/test/custom_harmony.js b/test/custom_harmony.js
new file mode 100644
index 0000000..48bec62
--- /dev/null
+++ b/test/custom_harmony.js
@@ -0,0 +1,24 @@
+/*
+ * grunt-express-server
+ * https://github.com/ericclemmons/grunt-express-server
+ *
+ * Copyright (c) 2013 Eric Clemmons
+ * Licensed under the MIT license.
+ */
+
+'use strict';
+
+var get = require('./lib/get');
+
+module.exports.custom_args = {
+  test_runs_in_harmony: function(test) {
+    test.expect(2);
+    get('http://localhost:3000/harmony', function(res, body) {
+      test.equal(res.statusCode, 200, 'should return 200');
+      test.equal(body, 'Harmony flag idx is 0');
+      test.done();
+    }, function(err) {
+      test.done();
+    });
+  }
+};
diff --git a/test/custom_node_env_test.js b/test/custom_node_env_test.js
index e3d2688..9f74646 100644
--- a/test/custom_node_env_test.js
+++ b/test/custom_node_env_test.js
@@ -13,7 +13,6 @@ var get = require('./lib/get');
 module.exports.custom_node_env = {
   test_site_configured_for_production: function(test) {
     test.expect(2);
-
     get('http://localhost:3000/env', function(res, body) {
       test.equal(res.statusCode, 200, 'should return 200');
       test.equal(body, 'Howdy from production!', 'should return dynamic page');