--- a/cubicweb/web/views/authentication.py	Mon Mar 05 10:32:58 2018 +0100
+++ b/cubicweb/web/views/authentication.py	Thu Feb 15 11:02:48 2018 +0100
@@ -17,6 +17,8 @@
 # with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
 """user authentication component"""
 
+from six import text_type
+
 from logilab.common.deprecation import class_renamed
 from logilab.common.textutils import unormalize
 
@@ -113,7 +115,7 @@
         self.data = {}
 
     def __unicode__(self):
-        return '<session %s (0x%x)>' % (unicode(self.user.login), id(self))
+        return '<session %s (0x%x)>' % (text_type(self.user.login), id(self))
 
     @property
     def anonymous_session(self):