diff --git a/wagtail_modeltranslation/static/wagtail_modeltranslation/js/wagtail_translated_slugs.js b/wagtail_modeltranslation/static/wagtail_modeltranslation/js/wagtail_translated_slugs.js
index e7fcea8..a404725 100644
--- a/wagtail_modeltranslation/static/wagtail_modeltranslation/js/wagtail_translated_slugs.js
+++ b/wagtail_modeltranslation/static/wagtail_modeltranslation/js/wagtail_translated_slugs.js
@@ -1,6 +1,6 @@
 $(document).ready(function () {
     isLive = $('body').hasClass('page-is-live');
-    if(!wagtailModelTranslations.translate_slugs) {
+    if (!wagtailModelTranslations.translate_slugs) {
         lang_code = wagtailModelTranslations.defaultLanguage.replace("-", "_");
         title_selector = '#id_title_' + lang_code;
         slug_selector = '#id_slug';
@@ -19,6 +19,49 @@ $(document).ready(function () {
     }
 });
 
+/**
+ * Returns the supplied string as a slug optionally using the vendor URLify util.
+ * If not using URLify it will read the global unicodeSlugsEnabled and return a slugified string.
+ * 
+ * HACK this function has been removed from Wagtail 5+, we restore it temporarily
+ *      to allow for slug generation to work as before, but it should be replaced
+ *      with the current slug generation system in use by Wagtail
+ *
+ * @param {string} val - value to be parsed into a slug
+ * @param {boolean} useURLify - if true, the vendor URLify will be used
+ * @returns {string}
+ */
+function cleanForSlug(
+    val,
+    useURLify,
+    { unicodeSlugsEnabled = window.unicodeSlugsEnabled } = {}
+) {
+    if (useURLify) {
+        // URLify performs extra processing on the string (e.g. removing stopwords) and is more suitable
+        // for creating a slug from the title, rather than sanitising a slug entered manually
+        const cleaned = window.URLify(val, 255);
+
+        // if the result is blank (e.g. because the title consisted entirely of stopwords),
+        // fall through to the non-URLify method
+        if (cleaned) {
+            return cleaned;
+        }
+    }
+
+    // just do the "replace"
+    if (unicodeSlugsEnabled) {
+        return val
+            .replace(/\s+/g, '-')
+            .replace(/[&/\\#,+()$~%.'":`@^!*?<>{}]/g, '')
+            .toLowerCase();
+    }
+
+    return val
+        .replace(/\s+/g, '-')
+        .replace(/[^A-Za-z0-9\-_]/g, '')
+        .toLowerCase();
+}
+
 function slugAutoPopulateTranslation(title_selector, slug_selector) {
     var slugFollowsTitle = false;