diff --git a/addons/survey/static/src/js/survey_result.js b/addons/survey/static/src/js/survey_result.js
index e6a8905c209..c70280c727e 100644
--- a/addons/survey/static/src/js/survey_result.js
+++ b/addons/survey/static/src/js/survey_result.js
@@ -1,7 +1,7 @@
 /** @odoo-module **/
 
 import { _t } from "@web/core/l10n/translation";
-import { loadBundle, loadJS } from "@web/core/assets";
+import { loadBundle } from "@web/core/assets";
 import { SurveyImageZoomer } from "@survey/js/survey_image_zoomer";
 import publicWidget from "@web/legacy/js/public/public_widget";
 
@@ -482,15 +482,6 @@ publicWidget.registry.SurveyResultWidget = publicWidget.Widget.extend({
     // Widget
     //--------------------------------------------------------------------------
 
-    /**
-    * @override
-    */
-    willStart: function () {
-        var url = '/web/webclient/locale/' + (document.documentElement.getAttribute('lang') || 'en_US').replace('-', '_');
-        var localeReady = loadJS(url);
-        return Promise.all([this._super.apply(this, arguments), localeReady]);
-    },
-
     /**
     * @override
     */
diff --git a/addons/web/controllers/webclient.py b/addons/web/controllers/webclient.py
index a2fdfe10492..a1b29354cb0 100644
--- a/addons/web/controllers/webclient.py
+++ b/addons/web/controllers/webclient.py
@@ -29,32 +29,11 @@ def CONTENT_MAXAGE():
     return http.STATIC_CACHE_LONG
 
 
-MOMENTJS_LANG_CODES_MAP = {
-    "sr_RS": "sr_cyrl",
-    "sr@latin": "sr"
-}
-
-
 class WebClient(http.Controller):
 
+    # FIXME: to be removed in master, deprecated since momentjs removal in commit 4327c062d820
     @http.route('/web/webclient/locale/<string:lang>', type='http', auth="none")
     def load_locale(self, lang):
-        lang = MOMENTJS_LANG_CODES_MAP.get(lang, lang)
-        magic_file_finding = [lang.replace("_", '-').lower(), lang.split('_')[0]]
-        for code in magic_file_finding:
-            try:
-                return http.Response(
-                    werkzeug.wsgi.wrap_file(
-                        request.httprequest.environ,
-                        file_open(f'web/static/lib/moment/locale/{code}.js', 'rb')
-                    ),
-                    content_type='application/javascript; charset=utf-8',
-                    headers=[('Cache-Control', f'max-age={http.STATIC_CACHE}')],
-                    direct_passthrough=True,
-                )
-            except IOError:
-                _logger.debug("No moment locale for code %s", code)
-
         return request.make_response("", headers=[
             ('Content-Type', 'application/javascript'),
             ('Cache-Control', f'max-age={http.STATIC_CACHE}'),
diff --git a/addons/web/static/src/legacy/js/public/public_root.js b/addons/web/static/src/legacy/js/public/public_root.js
index a87c2d1a98e..86793f50a8c 100644
--- a/addons/web/static/src/legacy/js/public/public_root.js
+++ b/addons/web/static/src/legacy/js/public/public_root.js
@@ -8,7 +8,7 @@ import { registry } from '@web/core/registry';
 import lazyloader from "@web/legacy/js/public/lazyloader";
 
 import { makeEnv, startServices } from "@web/env";
-import { loadJS, templates } from '@web/core/assets';
+import { templates } from '@web/core/assets';
 import { MainComponentsContainer } from "@web/core/main_components_container";
 import { browser } from '@web/core/browser/browser';
 import { _t } from "@web/core/l10n/translation";
@@ -24,8 +24,6 @@ function getLang() {
     return (html.getAttribute('lang') || 'en_US').replace('-', '_');
 }
 const lang = cookie.get('frontend_lang') || getLang(); // FIXME the cookie value should maybe be in the ctx?
-// momentjs don't have config for en_US, so avoid useless RPC
-var localeDef = lang !== 'en_US' ? loadJS('/web/webclient/locale/' + lang.replace('-', '_')) : Promise.resolve();
 
 
 /**
@@ -55,16 +53,6 @@ export const PublicRoot = publicWidget.RootWidget.extend({
         this.env = env;
         this.publicWidgets = [];
     },
-    /**
-     * @override
-     */
-    willStart: function () {
-        // TODO would be even greater to wait for localeDef only when necessary
-        return Promise.all([
-            this._super.apply(this, arguments),
-            localeDef
-        ]);
-    },
     /**
      * @override
      */