Deploying node.js application to Heroku

Using the dead simple tutorial on Heroku's website and when I run git push heroku master I receive the following error:

       Using Node.js version: 0.4.7
       Using npm version: 1.0.106
-----> Fetching Node.js binaries
-----> Vendoring node into slug
-----> Installing dependencies with npm
       npm ERR! Couldn't read dependencies.
       npm ERR! Failed to parse json
       npm ERR! Unexpected token }
       npm ERR! File: /tmp/build_17bicinzz6vv0/package.json
       npm ERR! JSON.parse Failed to parse package.json data.
       npm ERR! JSON.parse package.json must be actual JSON, not just JavaScript.
       npm ERR! JSON.parse 
       npm ERR! JSON.parse This is not a bug in npm.
       npm ERR! JSON.parse Tell the package author to fix their package.json file.
       npm ERR! 
       npm ERR! System Linux 2.6.32-343-ec2
       npm ERR! command "/tmp/node-node-c3iD/bin/node" "/tmp/node-npm-E95q/cli.js" "install" "--production"
       npm ERR! cwd /tmp/build_17bicinzz6vv0
       npm ERR! node -v v0.4.7
       npm ERR! npm -v 1.0.106
       npm ERR! file /tmp/build_17bicinzz6vv0/package.json
       npm ERR! code EJSONPARSE
       npm ERR! 
       npm ERR! Additional logging details can be found in:
       npm ERR!     /tmp/build_17bicinzz6vv0/npm-debug.log
       npm not ok
 !     Failed to install --production dependencies with npm
 !     Heroku push rejected, failed to compile Node.js app

My package.json is:

{
  "name": "node-example",
  "version": "0.0.1",
  "dependencies": {
    "express": "2.2.0"
  }
}

There's absolutely nothing wrong with my JSON, which I got from their tutorial, because when I run it locally, it works great. Why am I getting this error?