diff --git a/loading.html b/loading.html
index e50cf846b..6ec35bd53 100644
--- a/loading.html
+++ b/loading.html
@@ -22,7 +22,6 @@
       <div class="message"></div>
     </div>
     <script type="text/javascript" src="js/components.js"></script>
-    <script type="text/javascript" src="ts/backboneJquery.js"></script>
-    <script type="text/javascript" src="js/loading_start.js"></script>
+    <script type="text/javascript" src="ts/windows/loading/start.js"></script>
   </body>
 </html>
diff --git a/loading_preload.js b/loading_preload.js
deleted file mode 100644
index 03c4f46a5..000000000
--- a/loading_preload.js
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2020 Signal Messenger, LLC
-// SPDX-License-Identifier: AGPL-3.0-only
-
-/* global window */
-
-const { ipcRenderer } = require('electron');
-
-const url = require('url');
-const i18n = require('./js/modules/i18n');
-
-const config = url.parse(window.location.toString(), true).query;
-const { locale } = config;
-const localeMessages = ipcRenderer.sendSync('locale-data');
-
-window.i18n = i18n.setup(locale, localeMessages);
-window.Backbone = require('backbone');
diff --git a/main.js b/main.js
index 560b3a546..ded3862e8 100644
--- a/main.js
+++ b/main.js
@@ -1253,7 +1253,8 @@ app.on('ready', async () => {
       webPreferences: {
         ...defaultWebPrefs,
         nodeIntegration: false,
-        preload: path.join(__dirname, 'loading_preload.js'),
+        contextIsolation: false,
+        preload: path.join(__dirname, 'ts', 'windows', 'loading', 'preload.js'),
       },
       icon: windowIcon,
     });
diff --git a/package.json b/package.json
index 078224de3..3b77c518a 100644
--- a/package.json
+++ b/package.json
@@ -412,7 +412,6 @@
       "settings_preload.js",
       "permissions_popup_preload.js",
       "debug_log_preload.js",
-      "loading_preload.js",
       "main.js",
       "images/**",
       "fonts/**",
diff --git a/ts/util/lint/exceptions.json b/ts/util/lint/exceptions.json
index f1272a200..3a34ec827 100644
--- a/ts/util/lint/exceptions.json
+++ b/ts/util/lint/exceptions.json
@@ -170,20 +170,6 @@
     "updated": "2018-09-19T18:13:29.628Z",
     "reasonDetail": "Interacting with already-existing DOM nodes"
   },
-  {
-    "rule": "jQuery-$(",
-    "path": "js/loading_start.js",
-    "line": "$(() => {",
-    "reasonCategory": "usageTrusted",
-    "updated": "2020-03-25T15:45:04.024Z"
-  },
-  {
-    "rule": "jQuery-$(",
-    "path": "js/loading_start.js",
-    "line": "  $('.message').text(window.i18n('optimizingApplication'));",
-    "reasonCategory": "usageTrusted",
-    "updated": "2020-03-25T15:45:04.024Z"
-  },
   {
     "rule": "jQuery-load(",
     "path": "js/modules/emojis.js",
@@ -14455,5 +14441,33 @@
     "line": "  const lastFocusedRef = React.useRef<HTMLElement | null>(null);",
     "reasonCategory": "usageTrusted",
     "updated": "2021-07-30T16:57:33.618Z"
+  },
+  {
+    "rule": "jQuery-$(",
+    "path": "ts/windows/loading/start.js",
+    "line": "$(() => {",
+    "reasonCategory": "usageTrusted",
+    "updated": "2020-03-25T15:45:04.024Z"
+  },
+  {
+    "rule": "jQuery-$(",
+    "path": "ts/windows/loading/start.js",
+    "line": "    $('.message').text(window.i18n('optimizingApplication'));",
+    "reasonCategory": "usageTrusted",
+    "updated": "2021-07-22T03:00:34.561Z"
+  },
+  {
+    "rule": "jQuery-$(",
+    "path": "ts/windows/loading/start.ts",
+    "line": "  $('.message').text(window.i18n('optimizingApplication'));",
+    "reasonCategory": "usageTrusted",
+    "updated": "2020-03-25T15:45:04.024Z"
+  },
+  {
+    "rule": "jQuery-$(",
+    "path": "ts/windows/loading/start.ts",
+    "line": "$(() => {",
+    "reasonCategory": "usageTrusted",
+    "updated": "2021-07-22T03:00:34.561Z"
   }
 ]
\ No newline at end of file
diff --git a/ts/windows/loading/preload.ts b/ts/windows/loading/preload.ts
new file mode 100644
index 000000000..40470c2a8
--- /dev/null
+++ b/ts/windows/loading/preload.ts
@@ -0,0 +1,19 @@
+// Copyright 2020-2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { ipcRenderer } from 'electron';
+import * as url from 'url';
+import * as i18n from '../../../js/modules/i18n';
+import { strictAssert } from '../../util/assert';
+
+const config = url.parse(window.location.toString(), true).query;
+
+const { locale } = config;
+strictAssert(
+  typeof locale === 'string',
+  'Expected to be configured with a string locale'
+);
+
+const localeMessages = ipcRenderer.sendSync('locale-data');
+
+window.i18n = i18n.setup(locale, localeMessages);
diff --git a/js/loading_start.js b/ts/windows/loading/start.ts
similarity index 67%
rename from js/loading_start.js
rename to ts/windows/loading/start.ts
index 548be1b0b..6bc7c059e 100644
--- a/js/loading_start.js
+++ b/ts/windows/loading/start.ts
@@ -1,8 +1,6 @@
-// Copyright 2020 Signal Messenger, LLC
+// Copyright 2020-2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-/* global $ */
-
 $(() => {
   $('.message').text(window.i18n('optimizingApplication'));
 });