--- a/cubicweb/server/session.py	Wed Oct 05 10:17:39 2016 +0200
+++ b/cubicweb/server/session.py	Mon Jun 06 15:26:49 2016 +0200
@@ -305,7 +305,6 @@
         # other session utility
         if session.user.login == '__internal_manager__':
             self.user = session.user
-            self.set_language(self.user.prefered_language())
         else:
             self._set_user(session.user)