diff --git a/client/commonFramework/execute-challenge-stream.js b/client/commonFramework/execute-challenge-stream.js
index de7e102751..181868e581 100644
--- a/client/commonFramework/execute-challenge-stream.js
+++ b/client/commonFramework/execute-challenge-stream.js
@@ -15,6 +15,7 @@ window.common = (function(global) {
 
   common.executeChallenge$ = function executeChallenge$() {
     const code = common.editor.getValue();
+    const originalCode = code;
     const head = common.arrayToNewLineString(common.head);
     const tail = common.arrayToNewLineString(common.tail);
 
@@ -75,6 +76,7 @@ window.common = (function(global) {
               data,
               code,
               userTests,
+              originalCode,
               output: data.output.replace(/\\\"/gi, '')
             });
         });
diff --git a/client/commonFramework/run-tests-stream.js b/client/commonFramework/run-tests-stream.js
index b33718bb09..df5bc39dbd 100644
--- a/client/commonFramework/run-tests-stream.js
+++ b/client/commonFramework/run-tests-stream.js
@@ -5,14 +5,19 @@ window.common = (function(global) {
     common = { init: [] }
   } = global;
 
-  common.runTests$ = function runTests$({ code, userTests, ...rest }) {
+  common.runTests$ = function runTests$({
+    code,
+    originalCode,
+    userTests,
+    ...rest
+  }) {
 
     return Observable.from(userTests)
       .map(function(test) {
 
         /* eslint-disable no-unused-vars */
         const assert = chai.assert;
-        const editor = { getValue() { return code; }};
+        const editor = { getValue() { return originalCode; }};
         /* eslint-enable no-unused-vars */
 
         try {
diff --git a/client/commonFramework/update-preview.js b/client/commonFramework/update-preview.js
index 8d2a20c735..fb4e36d605 100644
--- a/client/commonFramework/update-preview.js
+++ b/client/commonFramework/update-preview.js
@@ -1,6 +1,6 @@
 window.common = (function(global) {
   const {
-    Rx: { Observable },
+    Rx: { BehaviorSubject, Observable },
     common = { init: [] }
   } = global;
 
@@ -27,6 +27,11 @@ window.common = (function(global) {
   const iFrameScript$ =
     common.getScriptContent$('/js/iFrameScripts.js').shareReplay();
 
+  // behavior subject allways remembers the last value
+  // we use this to determine if runPreviewTest$ is defined
+  // and prime it with false
+  common.previewReady$ = new BehaviorSubject(false);
+
   // runPreviewTests$ should be set up in the preview window
   common.runPreviewTests$ =
     () => Observable.throw({ err: new Error('run preview not enabled') });
@@ -42,13 +47,16 @@ window.common = (function(global) {
     return iFrameScript$
       .map(script => `<script>${script}</script>`)
       .flatMap(script => {
+        // we make sure to override the last value in the
+        // subject to false here.
+        common.previewReady$.onNext(false);
         preview.open();
         preview.write(libraryIncludes + code + '<!-- -->' + script);
         preview.close();
-        return Observable.fromCallback($(preview).ready, $(preview))()
-          .first()
-          // delay is need here for first initial run
-          .delay(100);
+        // now we filter false values and wait for the first true
+        return common.previewReady$
+          .filter(ready => ready)
+          .first();
       })
       .map(() => code);
   };
diff --git a/client/iFrameScripts.js b/client/iFrameScripts.js
index b4c9523317..7bbaa3eb10 100644
--- a/client/iFrameScripts.js
+++ b/client/iFrameScripts.js
@@ -35,4 +35,9 @@ window.__$(function() {
         .map(tests => ({ ...rest, tests }));
     };
 
+  // now that the runPreviewTest$ is defined
+  // we set the subject to true
+  // this will let the updatePreview
+  // script now that we are ready.
+  common.previewReady$.onNext(true);
 });