Deploying Meteor 0.9.2.1 on Heroku

When I try to deploy my Meteor app to Heroku, it crashes on boot.

Exception from task: Error: function expects no more than -1 arguments 
    at /app/.meteor/heroku_build/app/programs/server/node_modules/fibers/future.js:26:10 
    at readUtf8FileSync (packages/boilerplate-generator/boilerplate-generator.js:7) 
    at packages/boilerplate-generator/boilerplate-generator.js:82 
    at Array.forEach (native) 
    at Function._.each._.forEach (packages/underscore/underscore.js:105) 
    at Boilerplate._generateBoilerplateFromManifestAndSource (packages/boilerplate-generator/boilerplate-generator.js:64) 
    at new Boilerplate (packages/boilerplate-generator/boilerplate-generator.js:17) 
    at generateBoilerplateInstance (packages/webapp/webapp_server.js:288) 
    at packages/webapp/webapp_server.js:556 
    at Function._.each._.forEach (packages/underscore/underscore.js:113) 
    throw err;                                                                 
          ^ 
Error: function expects no more than -1 arguments 
    at Object.Future.wait (/app/.meteor/heroku_build/app/programs/server/node_modules/fibers/future.js:326:15) 
    at _.extend.runTask (packages/meteor/fiber_helpers.js:79) 
    at Object.WebAppInternals.generateBoilerplate (packages/webapp/webapp_server.js:553) 
    at Object.main (packages/webapp/webapp_server.js:773) 
    at /app/.meteor/heroku_build/app/programs/server/boot.js:194:27 
    - - - - - 
    at /app/.meteor/heroku_build/app/programs/server/node_modules/fibers/future.js:26:10 
    at readUtf8FileSync (packages/boilerplate-generator/boilerplate-generator.js:7) 
    at packages/boilerplate-generator/boilerplate-generator.js:82 
    at Array.forEach (native) 
    at Function._.each._.forEach (packages/underscore/underscore.js:105) 
    at Boilerplate._generateBoilerplateFromManifestAndSource (packages/boilerplate-generator/boilerplate-generator.js:64) 
    at new Boilerplate (packages/boilerplate-generator/boilerplate-generator.js:17) 
    at generateBoilerplateInstance (packages/webapp/webapp_server.js:288) 
    at packages/webapp/webapp_server.js:556 
    at Function._.each._.forEach (packages/underscore/underscore.js:113) 

It seems that Npm.require('fs').readFile.length is undefined.

I'm using this buildpack. When I build the app locally and test with node main.js it works. Are there any other changes that I need to make to the buildpack for Meteor 0.9.2.1?