diff --git a/app/i18n/index.js b/app/i18n/index.js
index 578c0bc45d..ff37535142 100644
--- a/app/i18n/index.js
+++ b/app/i18n/index.js
@@ -9,11 +9,11 @@ export const LANGUAGES = [
 		file: require('./locales/en').default
 	}, {
 		label: '简体中文',
-		value: 'zh-cn',
+		value: 'zh-CN',
 		file: require('./locales/zh-CN').default
 	}, {
 		label: '繁體中文',
-		value: 'zh-tw',
+		value: 'zh-TW',
 		file: require('./locales/zh-TW').default
 	}, {
 		label: 'Deutsch',
@@ -21,7 +21,7 @@ export const LANGUAGES = [
 		file: require('./locales/de').default
 	}, {
 		label: 'Español (ES)',
-		value: 'es',
+		value: 'es-ES',
 		file: require('./locales/es-ES').default
 	}, {
 		label: 'Français',
@@ -29,11 +29,11 @@ export const LANGUAGES = [
 		file: require('./locales/fr').default
 	}, {
 		label: 'Português (BR)',
-		value: 'pt-br',
+		value: 'pt-BR',
 		file: require('./locales/pt-BR').default
 	}, {
 		label: 'Português (PT)',
-		value: 'pt',
+		value: 'pt-PT',
 		file: require('./locales/pt-PT').default
 	}, {
 		label: 'Russian',
diff --git a/app/sagas/login.js b/app/sagas/login.js
index 7b64de0bc8..bd561cf6f3 100644
--- a/app/sagas/login.js
+++ b/app/sagas/login.js
@@ -18,7 +18,7 @@ import { roomsRequest } from '../actions/rooms';
 import { toMomentLocale } from '../utils/moment';
 import RocketChat from '../lib/rocketchat';
 import log, { logEvent, events } from '../utils/log';
-import I18n from '../i18n';
+import I18n, { LANGUAGES } from '../i18n';
 import database from '../lib/database';
 import EventEmitter from '../utils/events';
 import { inviteLinksRequest } from '../actions/inviteLinks';
@@ -267,8 +267,9 @@ const handleLogout = function* handleLogout({ forcedByServer }) {
 
 const handleSetUser = function* handleSetUser({ user }) {
 	if (user && user.language) {
-		I18n.locale = user.language;
-		moment.locale(toMomentLocale(user.language));
+		const locale = LANGUAGES.find(l => l.value.toLowerCase() === user.language)?.value || user.language;
+		I18n.locale = locale;
+		moment.locale(toMomentLocale(locale));
 	}
 
 	if (user && user.status) {