diff --git a/client/src/client/frame-runner.js b/client/src/client/frame-runner.js
index 774a4b39d68..e26a0b71a0e 100644
--- a/client/src/client/frame-runner.js
+++ b/client/src/client/frame-runner.js
@@ -4,7 +4,7 @@ document.addEventListener('DOMContentLoaded', function() {
     catchError,
     map,
     toArray,
-    switchMap,
+    mergeMap,
     of,
     from,
     throwError
@@ -65,7 +65,7 @@ document.addEventListener('DOMContentLoaded', function() {
     // Iterate through the test one at a time
     // on new stacks
     const results = from(tests).pipe(
-      switchMap(function runOneTest({ text, testString }) {
+      mergeMap(function runOneTest({ text, testString }) {
         const newTest = { text, testString };
         let test;
         let __result;
diff --git a/client/src/templates/Challenges/utils/frame.js b/client/src/templates/Challenges/utils/frame.js
index 3b3aebfbfa4..0bd30252afe 100644
--- a/client/src/templates/Challenges/utils/frame.js
+++ b/client/src/templates/Challenges/utils/frame.js
@@ -5,7 +5,7 @@ import {
   map,
   toArray,
   delay,
-  switchMap,
+  mergeMap,
   timeout,
   catchError
 } from 'rxjs/operators';
@@ -98,7 +98,7 @@ const addDepsToDocument = ctx => {
       map,
       toArray,
       delay,
-      switchMap,
+      mergeMap,
       timeout,
       catchError
     },