diff --git a/addon/runmode/runmode-standalone.js b/addon/runmode/runmode-standalone.js
index 9ebde8b0544c8c55fa7b983d82beec88c1f3e946..ec06ba11cbf36b072d52ed40ca031486090f9c29 100644
--- a/addon/runmode/runmode-standalone.js
+++ b/addon/runmode/runmode-standalone.js
@@ -91,6 +91,10 @@ CodeMirror.getMode = function (options, spec) {
   return mfactory(options, spec);
 };
 CodeMirror.registerHelper = CodeMirror.registerGlobalHelper = Math.min;
+CodeMirror.defineMode("null", function() {
+  return {token: function(stream) {stream.skipToEnd();}};
+});
+CodeMirror.defineMIME("text/plain", "null");
 
 CodeMirror.runMode = function (string, modespec, callback, options) {
   var mode = CodeMirror.getMode({ indentUnit: 2 }, modespec);