diff --git a/sao/src/sao.js b/sao/src/sao.js
index b1cefa776a..3b6c2cfee9 100644
--- a/sao/src/sao.js
+++ b/sao/src/sao.js
@@ -374,17 +374,22 @@ var Sao = {
                         });
                     }
                     return prm.then(() => {
-                        Sao.set_title();
-                        var new_lang = preferences.language != Sao.i18n.getLocale();
                         var prm = jQuery.Deferred();
-                        Sao.i18n.setlang(preferences.language).always(function() {
-                            if (new_lang) {
-                                Sao.user_menu(preferences);
-                            }
+                        Sao.set_title();
+                        if (!preferences.language) {
+                            session.context.language = Sao.i18n.getLocale();
                             prm.resolve(preferences);
-                        });
-                        Sao.i18n.set_direction(preferences.language_direction);
-                        Sao.i18n.locale = preferences.locale;
+                        } else {
+                            var new_lang = preferences.language != Sao.i18n.getLocale();
+                            Sao.i18n.setlang(preferences.language).always(function() {
+                                if (new_lang) {
+                                    Sao.user_menu(preferences);
+                                }
+                                prm.resolve(preferences);
+                            });
+                            Sao.i18n.set_direction(preferences.language_direction);
+                            Sao.i18n.locale = preferences.locale;
+                        }
                         Sao.common.MODELNAME.clear();
                         return prm;
                     });
diff --git a/tryton/tryton/gui/main.py b/tryton/tryton/gui/main.py
index 34ab14ef0d..a1ebfd5ea4 100644
--- a/tryton/tryton/gui/main.py
+++ b/tryton/tryton/gui/main.py
@@ -536,7 +536,7 @@ class Main(Gtk.Application):
             for target in targets:
                 target()
 
-        if prefs and 'language_direction' in prefs:
+        if prefs and prefs.get('language_direction'):
             translate.set_language_direction(prefs['language_direction'])
             CONFIG['client.language_direction'] = \
                 prefs['language_direction']
@@ -544,12 +544,14 @@ class Main(Gtk.Application):
         for action_id in prefs.get('actions', []):
             Action.execute(action_id, {})
         self.set_title(prefs.get('status_bar', ''))
-        if prefs and 'language' in prefs:
+        if prefs and prefs.get('language'):
             translate.setlang(prefs['language'], prefs.get('locale'))
             if CONFIG['client.lang'] != prefs['language']:
                 self.favorite_unset()
                 self.primary_menu.set_menu_model(self._get_primary_menu())
             CONFIG['client.lang'] = prefs['language']
+        else:
+            rpc.CONTEXT['language'] = CONFIG['client.lang']
         common.MODELNAME.clear()
         # Set placeholder after language is set to get correct translation
         self.global_search_entry.set_placeholder_text(_("Action"))
diff --git a/tryton/tryton/rpc.py b/tryton/tryton/rpc.py
index a31cf3e58c..e941862dac 100644
--- a/tryton/tryton/rpc.py
+++ b/tryton/tryton/rpc.py
@@ -38,6 +38,7 @@ def context_reset():
     from tryton.bus import Bus
     CONTEXT.clear()
     CONTEXT['client'] = Bus.ID
+    CONTEXT['language'] = CONFIG['client.lang']
 
 
 context_reset()
@@ -118,7 +119,7 @@ def login(parameters):
     port = common.get_port(host)
     database = CONFIG['login.db']
     username = CONFIG['login.login']
-    language = CONFIG['client.lang']
+    CONTEXT['language'] = language = CONFIG['client.lang']
     parameters['device_cookie'] = device_cookie.get()
     connection = ServerProxy(hostname, port, database)
     logger.info('common.db.login(%s, %s, %s)', username, 'x' * 10, language)