diff --git a/addons/web/static/src/js/core/translation.js b/addons/web/static/src/js/core/translation.js
index 169cf9422e8..81b220e1e76 100644
--- a/addons/web/static/src/js/core/translation.js
+++ b/addons/web/static/src/js/core/translation.js
@@ -70,9 +70,7 @@ var TranslationDataBase = Class.extend(/** @lends instance.TranslationDataBase#
         if (modules) {
             paramsGet.modules = modules.join(',');
         }
-        if (lang) {
-            paramsGet.lang = lang;
-        }
+        paramsGet.lang = lang || null;
         return $.get(url, paramsGet).then(function (trans) {
             self.set_bundle(trans);
         });