diff --git a/index.js b/index.js
index f330853..e584b59 100644
--- a/index.js
+++ b/index.js
@@ -109,9 +109,22 @@ module.exports = function packager (opts, cb) {
         var finalPath = path.join(opts.out || process.cwd(), opts.name + '.app')
 
         fs.rename(newApp, finalPath, function moved (err) {
-          cb(err, finalPath)
+          if (err) return cb(err)
+          updateMacIcon()
         })
       }
     })
   }
+
+  function updateMacIcon () {
+    var finalPath = path.join(opts.out || process.cwd(), opts.name + '.app')
+
+    if (!opts.icon) {
+      return cb(null, finalPath)
+    }
+
+    ncp(opts.icon, path.join(finalPath, 'Contents', 'Resources', 'atom.icns'), function copied (err) {
+      cb(err, finalPath)
+    })
+  }
 }
diff --git a/readme.md b/readme.md
index 786c80b..b8c7018 100644
--- a/readme.md
+++ b/readme.md
@@ -43,7 +43,7 @@ You should be able to double-click `AppName.app` to launch the app. If not, chec
 these are optional CLI options you can pass in
 
 - `out` (default current working dir) - the dir to put the app into at the end
-- `version` (default hardcoded in source) - electron version to use
+- `icon` - the icon file to use as the icon for the app
 - `app-bundle-id` - bundle identifier to use in the app plist
 - `helper-bundle-id` - bundle identifier to use in the app helper plist
 - `ignore` (default none) - do not copy files into App whose filenames regex .match this string