diff --git a/addons/portal_anonymous/static/src/js/portal_anonymous.js b/addons/portal_anonymous/static/src/js/portal_anonymous.js
index adaa51948b5..9ca737b6947 100644
--- a/addons/portal_anonymous/static/src/js/portal_anonymous.js
+++ b/addons/portal_anonymous/static/src/js/portal_anonymous.js
@@ -1,5 +1,23 @@
 openerp.portal_anonymous = function(instance) {
 
+    instance.web.Session.include({
+        load_translations: function() {
+            var self = this;
+            if (self.username === 'anonymous') {
+                var browser_lang = (navigator.language || navigator.userLanguage).replace('-', '_');
+                if (browser_lang.length === 2) {
+                    return (new instance.web.Model('res.lang')).query(['code'])
+                        .filter([['iso_code', '=', browser_lang]]).all()
+                        .then(function(result) {
+                            self.user_context.lang = result[0].code;
+                        });
+                }
+                self.user_context.lang = browser_lang;
+            }
+            return self._super();
+        },
+    });
+
     instance.web.Login.include({
         start: function() {
             var self = this;