diff --git a/client/src/templates/Challenges/rechallenge/transformers.js b/client/src/templates/Challenges/rechallenge/transformers.js
index a47a1e4f0d..e0774287b9 100644
--- a/client/src/templates/Challenges/rechallenge/transformers.js
+++ b/client/src/templates/Challenges/rechallenge/transformers.js
@@ -44,18 +44,22 @@ Babel.registerPlugin(
   protect(testProtectTimeout, testLoopProtectCB, loopsPerTimeoutCheck)
 );
 
+const babelOptionsJSBase = {
+  presets: [presetEnv]
+};
+
 const babelOptionsJSX = {
   plugins: ['loopProtection'],
   presets: [presetEnv, presetReact]
 };
 
 const babelOptionsJS = {
-  plugins: ['testLoopProtection'],
-  presets: [presetEnv]
+  ...babelOptionsJSBase,
+  plugins: ['testLoopProtection']
 };
 
 const babelOptionsJSPreview = {
-  ...babelOptionsJS,
+  ...babelOptionsJSBase,
   plugins: ['loopProtection']
 };
 
@@ -94,16 +98,22 @@ function tryTransform(wrap = identity) {
   };
 }
 
-const babelTransformer = (preview = false) =>
-  cond([
+const babelTransformer = ({ preview = false, protect = true }) => {
+  let options = babelOptionsJSBase;
+  // we always protect the preview, since it evaluates as the user types and
+  // they may briefly have infinite looping code accidentally
+  if (protect) {
+    options = preview ? babelOptionsJSPreview : babelOptionsJS;
+  } else {
+    options = preview ? babelOptionsJSPreview : options;
+  }
+  return cond([
     [
       testJS,
       flow(
         partial(
           vinyl.transformHeadTailAndContents,
-          tryTransform(
-            babelTransformCode(preview ? babelOptionsJSPreview : babelOptionsJS)
-          )
+          tryTransform(babelTransformCode(options))
         )
       )
     ],
@@ -119,6 +129,7 @@ const babelTransformer = (preview = false) =>
     ],
     [stubTrue, identity]
   ]);
+};
 
 const sassWorker = createWorker(sassCompile);
 async function transformSASS(element) {
@@ -167,16 +178,9 @@ export const htmlTransformer = cond([
   [stubTrue, identity]
 ]);
 
-export const transformers = [
+export const getTransformers = config => [
   replaceNBSP,
-  babelTransformer(),
-  composeHTML,
-  htmlTransformer
-];
-
-export const transformersPreview = [
-  replaceNBSP,
-  babelTransformer(true),
+  babelTransformer(config ? config : {}),
   composeHTML,
   htmlTransformer
 ];
diff --git a/client/src/templates/Challenges/redux/execute-challenge-saga.js b/client/src/templates/Challenges/redux/execute-challenge-saga.js
index b5048181f1..d3dac046ad 100644
--- a/client/src/templates/Challenges/redux/execute-challenge-saga.js
+++ b/client/src/templates/Challenges/redux/execute-challenge-saga.js
@@ -15,6 +15,7 @@ import escape from 'lodash/escape';
 
 import {
   challengeDataSelector,
+  challengeMetaSelector,
   challengeTestsSelector,
   initConsole,
   updateConsole,
@@ -33,7 +34,8 @@ import {
   getTestRunner,
   challengeHasPreview,
   updatePreview,
-  isJavaScriptChallenge
+  isJavaScriptChallenge,
+  isLoopProtected
 } from '../utils/build';
 
 // How long before bailing out of a preview.
@@ -67,7 +69,12 @@ export function* executeChallengeSaga() {
     const proxyLogger = args => consoleProxy.put(args);
 
     const challengeData = yield select(challengeDataSelector);
-    const buildData = yield buildChallengeData(challengeData);
+    const challengeMeta = yield select(challengeMetaSelector);
+    const protect = isLoopProtected(challengeMeta);
+    const buildData = yield buildChallengeData(challengeData, {
+      preview: false,
+      protect
+    });
     const document = yield getContext('document');
     const testRunner = yield call(
       getTestRunner,
@@ -103,9 +110,9 @@ function* takeEveryConsole(channel) {
   });
 }
 
-function* buildChallengeData(challengeData, preview) {
+function* buildChallengeData(challengeData, options) {
   try {
-    return yield call(buildChallenge, challengeData, preview);
+    return yield call(buildChallenge, challengeData, options);
   } catch (e) {
     yield put(disableBuildOnError());
     throw e;
@@ -167,8 +174,14 @@ function* previewChallengeSaga() {
     yield fork(takeEveryConsole, logProxy);
 
     const challengeData = yield select(challengeDataSelector);
+
     if (canBuildChallenge(challengeData)) {
-      const buildData = yield buildChallengeData(challengeData, true);
+      const challengeMeta = yield select(challengeMetaSelector);
+      const protect = isLoopProtected(challengeMeta);
+      const buildData = yield buildChallengeData(challengeData, {
+        preview: true,
+        protect
+      });
       // evaluate the user code in the preview frame or in the worker
       if (challengeHasPreview(challengeData)) {
         const document = yield getContext('document');
diff --git a/client/src/templates/Challenges/redux/index.js b/client/src/templates/Challenges/redux/index.js
index e8b1ff0444..8cb92f4a43 100644
--- a/client/src/templates/Challenges/redux/index.js
+++ b/client/src/templates/Challenges/redux/index.js
@@ -21,6 +21,7 @@ const initialState = {
   canFocusEditor: true,
   challengeFiles: {},
   challengeMeta: {
+    superBlock: '',
     block: '',
     id: '',
     nextChallengePath: '/',
diff --git a/client/src/templates/Challenges/utils/build.js b/client/src/templates/Challenges/utils/build.js
index 0121cd957f..99304b35ee 100644
--- a/client/src/templates/Challenges/utils/build.js
+++ b/client/src/templates/Challenges/utils/build.js
@@ -1,4 +1,4 @@
-import { transformers, transformersPreview } from '../rechallenge/transformers';
+import { getTransformers } from '../rechallenge/transformers';
 import { cssToHtml, jsToHtml, concatHtml } from '../rechallenge/builders.js';
 import { challengeTypes } from '../../../../utils/challengeTypes';
 import createWorker from './worker-executor';
@@ -76,11 +76,11 @@ export function canBuildChallenge(challengeData) {
   return buildFunctions.hasOwnProperty(challengeType);
 }
 
-export async function buildChallenge(challengeData, preview = false) {
+export async function buildChallenge(challengeData, options) {
   const { challengeType } = challengeData;
   let build = buildFunctions[challengeType];
   if (build) {
-    return build(challengeData, preview);
+    return build(challengeData, options);
   }
   throw new Error(`Cannot build challenge of type ${challengeType}`);
 }
@@ -123,7 +123,7 @@ export function buildDOMChallenge({ files, required = [], template = '' }) {
   const finalRequires = [...globalRequires, ...required, ...frameRunner];
   const loadEnzyme = Object.keys(files).some(key => files[key].ext === 'jsx');
   const toHtml = [jsToHtml, cssToHtml];
-  const pipeLine = composeFunctions(...transformers, ...toHtml);
+  const pipeLine = composeFunctions(...getTransformers(), ...toHtml);
   const finalFiles = Object.keys(files)
     .map(key => files[key])
     .map(pipeLine);
@@ -137,10 +137,9 @@ export function buildDOMChallenge({ files, required = [], template = '' }) {
     }));
 }
 
-export function buildJSChallenge({ files }, preview = false) {
-  const pipeLine = preview
-    ? composeFunctions(...transformersPreview)
-    : composeFunctions(...transformers);
+export function buildJSChallenge({ files }, options) {
+  const pipeLine = composeFunctions(...getTransformers(options));
+
   const finalFiles = Object.keys(files)
     .map(key => files[key])
     .map(pipeLine);
@@ -191,3 +190,7 @@ export function isJavaScriptChallenge({ challengeType }) {
     challengeType === challengeTypes.bonfire
   );
 }
+
+export function isLoopProtected(challengeMeta) {
+  return challengeMeta.superBlock !== 'Coding Interview Prep';
+}
diff --git a/client/utils/gatsby/challengePageCreator.js b/client/utils/gatsby/challengePageCreator.js
index 651f2399e9..9685196bb5 100644
--- a/client/utils/gatsby/challengePageCreator.js
+++ b/client/utils/gatsby/challengePageCreator.js
@@ -61,6 +61,7 @@ const getIntroIfRequired = (node, index, nodeArray) => {
 
 exports.createChallengePages = createPage => ({ node }, index, thisArray) => {
   const {
+    superBlock,
     block,
     fields: { slug },
     required = [],
@@ -77,6 +78,7 @@ exports.createChallengePages = createPage => ({ node }, index, thisArray) => {
     component: getTemplateComponent(challengeType),
     context: {
       challengeMeta: {
+        superBlock,
         block: block,
         introPath: getIntroIfRequired(node, index, thisArray),
         template,