diff --git a/packages/gatsby/src/cache-dir/loader.js b/packages/gatsby/src/cache-dir/loader.js
index 36fc8c6e17394..a4c0870566449 100644
--- a/packages/gatsby/src/cache-dir/loader.js
+++ b/packages/gatsby/src/cache-dir/loader.js
@@ -38,6 +38,8 @@ const sortPagesByCount = (a, b) => {
   }
 }
 
+const prefetcher = () => {}
+
 const queue = {
   empty: () => {
     pathArray = []
@@ -46,7 +48,6 @@ const queue = {
     resourcesArray = []
     pages = []
   },
-  // Make pages injectable cause testing.
   addPagesArray: newPages => {
     pages = newPages
     findPage = pageFinderFactor(newPages)
@@ -144,6 +145,7 @@ const queue = {
       console.log("need to load scripts")
       const page = findPage(path)
       console.log("for page", page)
+      console.log(`async requires`, asyncRequires)
       let component
       let json
       const done = () => {
@@ -155,12 +157,19 @@ const queue = {
           })
         }
       }
-      asyncRequires.components[page.componentChunkName](c => {
-        component = preferDefault(c)
-        done()
-      })
-      asyncRequires.json[page.jsonName](j => {
-        json = preferDefault(j)
+      console.log(asyncRequires.components[page.componentChunkName])
+      console.log(asyncRequires.json[page.jsonName])
+      asyncRequires.components[page.componentChunkName]()(
+        callback => {
+          component = preferDefault(callback())
+          console.log(`page component`, component)
+          done()
+        },
+        () => console.log("error loading page component")
+      )
+      asyncRequires.json[page.jsonName]()(callback => {
+        json = preferDefault(callback())
+        console.log(`json`, json)
         done()
       })
     }
diff --git a/packages/gatsby/src/cache-dir/production-app.js b/packages/gatsby/src/cache-dir/production-app.js
index 92508f884119f..dde6cd01e16cc 100644
--- a/packages/gatsby/src/cache-dir/production-app.js
+++ b/packages/gatsby/src/cache-dir/production-app.js
@@ -19,10 +19,11 @@ window.___emitter = mitt()
 
 import pages from "./pages.json"
 import ComponentRenderer from "./component-renderer"
-import requires from "./async-requires"
+import asyncRequires from "./async-requires"
 import loader from "./loader"
 loader.addPagesArray(pages)
-loader.addProdRequires(requires)
+loader.addProdRequires(asyncRequires)
+window.asyncRequires = asyncRequires
 
 window.___loader = loader
 
@@ -185,9 +186,9 @@ let layout
 // }
 
 const loadLayout = cb => {
-  console.log(requires)
-  if (requires.layouts[`index`]) {
-    requires.layouts[`index`](cb)
+  console.log(asyncRequires)
+  if (asyncRequires.layouts[`index`]) {
+    asyncRequires.layouts[`index`](cb)
   } else {
     cb(props => <div>{props.children()}</div>)
   }
diff --git a/packages/gatsby/src/cache-dir/static-entry.js b/packages/gatsby/src/cache-dir/static-entry.js
index 8ff4f4e331217..a789d26aa0e34 100644
--- a/packages/gatsby/src/cache-dir/static-entry.js
+++ b/packages/gatsby/src/cache-dir/static-entry.js
@@ -1,7 +1,7 @@
 import React from "react"
 import { renderToString, renderToStaticMarkup } from "react-dom/server"
 import { StaticRouter, Route, withRouter } from "react-router-dom"
-import { kebabCase, get, merge, isArray } from "lodash"
+import { kebabCase, get, merge, isArray, isString } from "lodash"
 import apiRunner from "./api-runner-ssr"
 import pages from "./pages.json"
 import syncRequires from "./sync-requires"
@@ -149,19 +149,19 @@ module.exports = (locals, callback) => {
       if (prefixedScript === `/`) {
         return
       }
+
+      return prefixedScript
     })
-    .filter(s => s)
+    .filter(s => isString(s))
 
   scripts.forEach(script => {
     // Add preload <link>s for scripts.
-    headComponents.unshift(
-      <link rel="preload" href={prefixedScript} as="script" />
-    )
+    headComponents.unshift(<link rel="preload" href={script} as="script" />)
   })
 
   // Add script loader for page scripts to the head.
   // Taken from https://www.html5rocks.com/en/tutorials/speed/script-loading/
-  const scriptsString = scripts.map(s => `"${prefixedScript}"`).join(`,`)
+  const scriptsString = scripts.map(s => `"${s}"`).join(`,`)
   headComponents.push(
     <script
       dangerouslySetInnerHTML={{
diff --git a/packages/gatsby/src/internal-plugins/query-runner/pages-writer.js b/packages/gatsby/src/internal-plugins/query-runner/pages-writer.js
index 3004e4b53eb6d..da6d462a748ff 100644
--- a/packages/gatsby/src/internal-plugins/query-runner/pages-writer.js
+++ b/packages/gatsby/src/internal-plugins/query-runner/pages-writer.js
@@ -107,7 +107,7 @@ const preferDefault = m => m && m.default || m
   asyncRequires += `exports.components = {\n${components
     .map(
       c =>
-        `  "${c.componentChunkName}": require("bundle-loader?lazy&name=${c.componentChunkName}!${joinPath(
+        `  "${c.componentChunkName}": require("gatsby-module-loader?name=${c.componentChunkName}!${joinPath(
           c.component
         )}")`
     )
@@ -116,7 +116,7 @@ const preferDefault = m => m && m.default || m
   asyncRequires += `exports.json = {\n${json
     .map(
       j =>
-        `  "${j.jsonName}": require("bundle-loader?lazy&name=${pathChunkName(
+        `  "${j.jsonName}": require("gatsby-module-loader?name=${pathChunkName(
           j.path
         )}!${joinPath(program.directory, `/.cache/json/`, j.jsonName)}")`
     )
@@ -127,7 +127,7 @@ const preferDefault = m => m && m.default || m
       let componentName = layout
       if (layout !== false || typeof layout !== `undefined`) {
         componentName = `index`
-        return `  "${layout}": require("bundle-loader?lazy&name=${`layout-component---${layout}`}!${joinPath(
+        return `  "${layout}": require("gatsby-module-loader?name=${`layout-component---${layout}`}!${joinPath(
           program.directory,
           `/src/layouts/`,
           componentName
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/.gitignore b/packages/gatsby/src/loaders/gatsby-module-loader/.gitignore
new file mode 100644
index 0000000000000..3c3629e647f5d
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/README.md b/packages/gatsby/src/loaders/gatsby-module-loader/README.md
new file mode 100644
index 0000000000000..4a843c7e49778
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/README.md
@@ -0,0 +1,5 @@
+# `gatsby-module-loader` for webpack
+
+_Based on https://github.com/webpack/bundle-loader and https://github.com/NekR/async-module-loader_
+
+Is lazy and chunk execution is always deferred + there's good error handling.
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/index.js b/packages/gatsby/src/loaders/gatsby-module-loader/index.js
new file mode 100644
index 0000000000000..d0c90c552682a
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/index.js
@@ -0,0 +1,58 @@
+/*
+  Based on Tobias Koppers @sokra bundle-loader
+  https://github.com/webpack/bundle-loader
+
+  and Arthur Stolyar's async-module-loader
+*/
+const loaderUtils = require(`loader-utils`)
+const path = require(`path`)
+console.log("in gatsby-module-loader")
+
+module.exports = function() {}
+module.exports.pitch = function(remainingRequest) {
+  this.cacheable && this.cacheable()
+
+  console.log("this.query", this.query)
+  const query = loaderUtils.parseQuery(this.query)
+  console.log("query", query)
+  let chunkName = ``
+
+  if (query.name) {
+    chunkName = loaderUtils.interpolateName(this, query.name, {
+      context: query.context,
+      regExp: query.regExp,
+    })
+    chunkName = `, ${JSON.stringify(chunkName)}`
+  }
+
+  console.log(`chunkName`, chunkName)
+
+  const request = loaderUtils.stringifyRequest(this, `!!` + remainingRequest)
+
+  const callback = "callback(function() { return require(" + request + ") })"
+
+  const executor = `
+    return function(callback, errback) {
+      require.ensure([], function(_, error) {
+        if (error) {
+          errback()
+        } else {
+          ${callback}
+        }
+      }${chunkName});
+    }`
+
+  const result = `
+    require(
+      ${loaderUtils.stringifyRequest(
+        this,
+        `!${path.join(__dirname, `patch.js`)}`
+      )}
+    );
+    module.exports = function() { ${executor} }
+    `
+
+  console.log(`result`, result)
+
+  return result
+}
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/package.json b/packages/gatsby/src/loaders/gatsby-module-loader/package.json
new file mode 100644
index 0000000000000..31c0e1ff848b0
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "gatsby-module-loader",
+  "version": "1.0.0",
+  "description": "_Based on https://github.com/webpack/bundle-loader and https://github.com/NekR/async-module-loader_",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "MIT"
+}
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/patch.js b/packages/gatsby/src/loaders/gatsby-module-loader/patch.js
new file mode 100644
index 0000000000000..1da59e6c58b7b
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/patch.js
@@ -0,0 +1,80 @@
+patch()
+
+function patch() {
+  var head = document.querySelector(`head`)
+  var ensure = __webpack_require__.e
+  var chunks = __webpack_require__.s
+  var failures
+
+  __webpack_require__.e = function(chunkId, callback) {
+    var loaded = false
+    var immediate = true
+
+    var handler = function(error) {
+      if (!callback) return
+
+      callback(__webpack_require__, error)
+      callback = null
+    }
+
+    if (!chunks && failures && failures[chunkId]) {
+      handler(true)
+      return
+    }
+
+    ensure(chunkId, function() {
+      if (loaded) return
+      loaded = true
+
+      if (immediate) {
+        // webpack fires callback immediately if chunk was already loaded
+        // IE also fires callback immediately if script was already
+        // in a cache (AppCache counts too)
+        setTimeout(function() {
+          handler()
+        })
+      } else {
+        handler()
+      }
+    })
+
+    // This is |true| if chunk is already loaded and does not need onError call.
+    // This happens because in such case ensure() is performed in sync way
+    if (loaded) {
+      return
+    }
+
+    immediate = false
+
+    onError(function() {
+      if (loaded) return
+      loaded = true
+
+      if (chunks) {
+        chunks[chunkId] = void 0
+      } else {
+        failures || (failures = {})
+        failures[chunkId] = true
+      }
+
+      handler(true)
+    })
+  }
+
+  function onError(callback) {
+    var script = head.lastChild
+
+    if (script.tagName !== `SCRIPT`) {
+      if (typeof console !== `undefined` && console.warn) {
+        console.warn(`Script is not a script`, script)
+      }
+
+      return
+    }
+
+    script.onload = script.onerror = function() {
+      script.onload = script.onerror = null
+      setTimeout(callback, 0)
+    }
+  };
+};
\ No newline at end of file
diff --git a/packages/gatsby/src/loaders/gatsby-module-loader/plugin.js b/packages/gatsby/src/loaders/gatsby-module-loader/plugin.js
new file mode 100644
index 0000000000000..c0b36a37aedfb
--- /dev/null
+++ b/packages/gatsby/src/loaders/gatsby-module-loader/plugin.js
@@ -0,0 +1,23 @@
+module.exports = function() {}
+module.exports.prototype.apply = function(compiler) {
+  compiler.plugin(`compilation`, function(compilation) {
+    compilation.mainTemplate.plugin(`require-extensions`, function(
+      source,
+      chunk,
+      hash
+    ) {
+      if (chunk.chunks.length > 0) {
+        var buf = []
+
+        buf.push(``)
+        buf.push(``)
+        buf.push(`// expose the chunks object`)
+        buf.push(this.requireFn + `.s = installedChunks;`)
+
+        return source + this.asString(buf)
+      }
+
+      return source
+    })
+  })
+}
diff --git a/packages/gatsby/src/utils/webpack.config.js b/packages/gatsby/src/utils/webpack.config.js
index 9bcaff78955db..e5f8d626126fa 100644
--- a/packages/gatsby/src/utils/webpack.config.js
+++ b/packages/gatsby/src/utils/webpack.config.js
@@ -15,6 +15,7 @@ const { store } = require(`../redux`)
 const debug = require(`debug`)(`gatsby:webpack-config`)
 const WebpackMD5Hash = require(`webpack-md5-hash`)
 const ChunkManifestPlugin = require(`chunk-manifest-webpack-plugin`)
+const GatsbyModulePlugin = require(`../loaders/gatsby-module-loader/plugin`)
 const genBabelConfig = require(`./babel-config`)
 
 // Five stages or modes:
@@ -268,6 +269,7 @@ module.exports = async (
           }),
           // Ensure module order stays the same. Supposibly fixed in webpack 2.0.
           new webpack.optimize.OccurenceOrderPlugin(),
+          new GatsbyModulePlugin(),
           // new WebpackStableModuleIdAndHash({ seed: 9, hashSize: 47 }),
           new webpack.NamedModulesPlugin(),
         ]
@@ -469,7 +471,7 @@ module.exports = async (
 
     return {
       root,
-      modulesDirectories: [`node_modules`],
+      modulesDirectories: [path.join(__dirname, `../loaders`), `node_modules`],
     }
   }