diff --git a/config.default.json b/config.default.json
index ee3b4ed5..b9bd9c91 100644
--- a/config.default.json
+++ b/config.default.json
@@ -5,7 +5,8 @@
     "host": "localhost:3000",
     "prefix": "/",
     "ssl": false,
-    "static": false
+    "static": false,
+    "runner": false
   },
   "max-request-size": "1MB",
   "store": {
diff --git a/lib/app.js b/lib/app.js
index 6d238605..1ab4cae1 100644
--- a/lib/app.js
+++ b/lib/app.js
@@ -85,9 +85,10 @@ if (!process.env.TZ && options.timezone) {
   options.port = port;
 })();
 
-// Strip trailing slash from the prefix.
+// Strip trailing slash from the prefix
 options.url.prefix = options.url.prefix.replace(/\/$/, '');
 
+
 // Apply the keys from the config file. All nested properties are
 // space delimited to match the express style.
 //
@@ -121,6 +122,14 @@ if (options.url.static) {
   app.set('static url', app.set('url full'));
 }
 
+if (options.url.runner) {
+  // strip trailing slash, just in case
+  options.url.runner = options.url.runner.replace(/\/$/, '');
+  app.set('url runner', options.url.runner);
+} else {
+  app.set('url runner', app.set('url full'));
+}
+
 app.engine('html', hogan.renderer).engine('txt', hogan.renderer);
 
 // Define some generic template variables.
diff --git a/lib/handlers/bin.js b/lib/handlers/bin.js
index e4ab3458..8028c085 100644
--- a/lib/handlers/bin.js
+++ b/lib/handlers/bin.js
@@ -617,6 +617,7 @@ module.exports = Observable.extend({
       version: version,
       token: req.session._csrf,
       root: root,
+      runner: helpers.runner,
       static: helpers.urlForStatic(),
       settings: !bin.url ? config && config.settings : {},
       // If we've pulled a just created bin out of the flash messages object
@@ -799,6 +800,7 @@ module.exports = Observable.extend({
   jsbin: function (bin, options) {
     return {
       root: options.root,
+      runner: this.helpers.runner,
       static: options.static || options.root,
       version: options.version,
       state: {
diff --git a/lib/helpers.js b/lib/helpers.js
index 65548cd5..8e92425e 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -11,6 +11,10 @@ module.exports.createHelpers = function createHelpers(app) {
     // Check to see if the app is in production.
     production: app.get('env') === app.PRODUCTION,
 
+
+    // Pre-set the URL used for the runner
+    runner: app.set('url runner') + '/runner',
+
     // Renders the analytics snippet. Accepts a callback that recieves
     // and error and html object.
     analytics: function (render, fn) {
diff --git a/lib/routes.js b/lib/routes.js
index 2bdbe50c..5d98ccd5 100644
--- a/lib/routes.js
+++ b/lib/routes.js
@@ -50,7 +50,7 @@ module.exports = function (app) {
   binHandler.on('latest-for-user', spike.updateUserSpikes.bind(spike));
   binHandler.on('new-revision', spike.bumpRevision.bind(spike));
 
-  binHandler.on('render-scripts', spike.appendScripts.bind(spike));
+  binHandler.on('render-scripts', spike.appendScripts.bind(spike, app.settings.version));
 
   // Load the bin from the store when encountered in the url. Also handles the
   // "latest" url action.
diff --git a/lib/spike/index.js b/lib/spike/index.js
index b7842452..d787ac99 100644
--- a/lib/spike/index.js
+++ b/lib/spike/index.js
@@ -300,11 +300,11 @@ module.exports = {
     }, delayTrigger);
   },
 
-  appendScripts: function (scripts) {
+  appendScripts: function (version, scripts) {
     // TODO this should really detect that there's an active session going
     // on and the user is saving, and therefore include the spike intelligently
-    scripts.push('js/vendor/eventsource.js');
-    scripts.push('js/spike.js');
+    scripts.push('js/vendor/eventsource.js?' + version);
+    scripts.push('js/spike.js?' + version);
   },
 
   utils: utils
diff --git a/package.json b/package.json
index 330890d5..ad40b10a 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
   "name": "jsbin",
   "description": "Collaborative JavaScript Debugging App",
   "main": "./lib/app",
-  "version": "3.7.1",
+  "version": "3.7.3",
   "preferGlobal": "true",
   "homepage": "http://jsbin.com",
   "bin": "./bin/jsbin",
diff --git a/public/js/render/live.js b/public/js/render/live.js
index 0f1f1a1f..c8da8772 100644
--- a/public/js/render/live.js
+++ b/public/js/render/live.js
@@ -264,7 +264,7 @@ var renderLivePreview = (function () {
     iframe.setAttribute('sandbox', 'allow-forms allow-pointer-lock allow-popups allow-same-origin allow-scripts');
     iframe.setAttribute('frameBorder', '0');
     $live.prepend(iframe);
-    iframe.src = jsbin.root.replace('jsbin', 'run.jsbin') + '/runner';
+    iframe.src = jsbin.runner;
     try {
       iframe.contentWindow.name = '/' + jsbin.state.code + '/' + jsbin.state.revision;
     } catch (e) {