diff --git a/app/assets/javascripts/discourse/tests/test-helper.js b/app/assets/javascripts/discourse/tests/test-helper.js
index 299a37c7807..f66fa1fe0d9 100644
--- a/app/assets/javascripts/discourse/tests/test-helper.js
+++ b/app/assets/javascripts/discourse/tests/test-helper.js
@@ -8,14 +8,16 @@ document.addEventListener("discourse-booted", () => {
   let setupTests = require("discourse/tests/setup-tests").default;
   Ember.ENV.LOG_STACKTRACE_ON_DEPRECATION = false;
 
-  document.write(`
-    <div id="qunit"></div>
-    <div id="qunit-fixture"></div>
-
-    <div id="ember-testing-container" style='position: fixed'>
-      <div id="ember-testing"></div>
-    </div>
-  `);
+  document.body.insertAdjacentHTML(
+    "afterbegin",
+    `
+      <div id="qunit"></div>
+      <div id="qunit-fixture"></div>
+      <div id="ember-testing-container" style="position: fixed">
+        <div id="ember-testing"></div>
+      </div>
+    `
+  );
 
   setupTests(config.APP);
   start({ setupTestContainer: false });
diff --git a/app/assets/javascripts/wizard/test/test_helper.js b/app/assets/javascripts/wizard/test/test_helper.js
index 9e9d3f99a83..f3ffbfce88f 100644
--- a/app/assets/javascripts/wizard/test/test_helper.js
+++ b/app/assets/javascripts/wizard/test/test_helper.js
@@ -24,14 +24,15 @@
 //= require ./wizard-pretender
 //= require test-shims
 
-// Trick JSHint into allow document.write
-let d = document;
-d.write(
-  '<div id="ember-testing-container"><div id="ember-testing"></div></div>'
-);
-d.write(
-  "<style>#ember-testing-container { position: absolute; background: white; bottom: 0; right: 0; width: 640px; height: 384px; overflow: auto; z-index: 9999; border: 1px solid #ccc; } #ember-testing { zoom: 50%; }</style>"
-);
+document.addEventListener("DOMContentLoaded", function () {
+  document.body.insertAdjacentHTML(
+    "afterbegin",
+    `
+      <div id="ember-testing-container"><div id="ember-testing"></div></div>
+      <style>#ember-testing-container { position: absolute; background: white; bottom: 0; right: 0; width: 640px; height: 384px; overflow: auto; z-index: 9999; border: 1px solid #ccc; } #ember-testing { zoom: 50%; }</style>
+    `
+  );
+});
 
 if (window.Logster) {
   Logster.enabled = false;