diff --git a/src/main.js b/src/main.js
index 4ea1b759b04..d458afd8dad 100644
--- a/src/main.js
+++ b/src/main.js
@@ -484,7 +484,7 @@ app.once('ready', function () {
 					boot({ locale: 'en', availableLanguages: {} });
 				} else {
 					// See above the comment about the loader and case sensitiviness
-					appLocale.toLowerCase();
+					appLocale = appLocale.toLowerCase();
 					getNLSConfiguration(appLocale).then((nlsConfig) => {
 						if (!nlsConfig) {
 							nlsConfig = { locale: appLocale, availableLanguages: {} };