diff --git a/PVE/Service/pveproxy.pm b/PVE/Service/pveproxy.pm
index b092438a..bb60b29e 100755
--- a/PVE/Service/pveproxy.pm
+++ b/PVE/Service/pveproxy.pm
@@ -10,6 +10,7 @@ use Encode;
 use URI;
 use URI::QueryParam;
 use Data::Dumper;
+use PVE::Cluster;
 use PVE::API2Tools;
 use PVE::API2;
 use PVE::APIServer::Formatter;
@@ -176,7 +177,7 @@ sub is_phone {
 sub get_index {
     my ($nodename, $server, $r, $args) = @_;
 
-    my $lang = 'en';
+    my $lang;
     my $username;
     my $token = 'null';
 
@@ -192,6 +193,11 @@ sub get_index {
 	}
     }
 
+    if (!$lang) {
+	my $dc_conf = PVE::Cluster::cfs_read_file('datacenter.cfg');
+	$lang = $dc_conf->{language} // 'en';
+    }
+
     $username = '' if !$username;
 
     my $mobile = is_phone($r->header('User-Agent')) ? 1 : 0;
diff --git a/www/index.html.tpl b/www/index.html.tpl
index a972e3aa..ae7f610f 100644
--- a/www/index.html.tpl
+++ b/www/index.html.tpl
@@ -26,6 +26,7 @@
     <script type="text/javascript">
     Proxmox = {
 	Setup: { auth_cookie_name: 'PVEAuthCookie' },
+	defaultLang: '[% lang %]',
 	UserName: '[% username %]',
 	CSRFPreventionToken: '[% token %]'
     };
diff --git a/www/manager6/window/LoginWindow.js b/www/manager6/window/LoginWindow.js
index 683fb54c..3ab5173c 100644
--- a/www/manager6/window/LoginWindow.js
+++ b/www/manager6/window/LoginWindow.js
@@ -164,7 +164,7 @@ Ext.define('PVE.window.LoginWindow', {
 	    {
 		xtype: 'proxmoxLanguageSelector',
 		fieldLabel: gettext('Language'),
-		value: Ext.util.Cookies.get('PVELangCookie') || 'en',
+		value: Ext.util.Cookies.get('PVELangCookie') || Proxmox.defaultLang || 'en',
 		name: 'lang',
 		reference: 'langField',
 		submitValue: false