diff --git a/ext/bg/js/settings/popup-preview-frame.js b/ext/bg/js/settings/popup-preview-frame.js
index 49409968..73326322 100644
--- a/ext/bg/js/settings/popup-preview-frame.js
+++ b/ext/bg/js/settings/popup-preview-frame.js
@@ -160,7 +160,7 @@ class SettingsPopupPreview {
         const source = new TextSourceRange(range, range.toString(), null);
 
         try {
-            await this.frontend.searchSource(source, 'script');
+            await this.frontend.onSearchSource(source, 'script');
         } finally {
             source.cleanup();
         }
diff --git a/ext/bg/settings-popup-preview.html b/ext/bg/settings-popup-preview.html
index 339467d4..b79363c7 100644
--- a/ext/bg/settings-popup-preview.html
+++ b/ext/bg/settings-popup-preview.html
@@ -119,6 +119,7 @@
 
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
+        <script src="/mixed/js/text-scanner.js"></script>
 
         <script src="/fg/js/api.js"></script>
         <script src="/fg/js/document.js"></script>