diff --git a/react/features/base/i18n/customNavigatorDetector.ts b/react/features/base/i18n/customNavigatorDetector.ts
index 2643390092..b512faf6ab 100644
--- a/react/features/base/i18n/customNavigatorDetector.ts
+++ b/react/features/base/i18n/customNavigatorDetector.ts
@@ -59,7 +59,7 @@ export default {
 function normalizeLanguage(language: string) {
     const [ lang, variant ] = language.replace('_', '-').split('-');
 
-    if (!variant || lang === variant) {
+    if (!variant || lang.toUpperCase() === variant.toUpperCase()) {
         return lang;
     }