diff -r ca3efd72e854 -r f94c812c3669 devtools/fill.py
--- a/devtools/fill.py	Fri Sep 18 14:50:44 2015 +0200
+++ b/devtools/fill.py	Thu Sep 17 11:07:36 2015 +0200
@@ -27,7 +27,7 @@
 from datetime import datetime, date, time, timedelta
 from decimal import Decimal
 
-from six import add_metaclass
+from six import text_type, add_metaclass
 from six.moves import range
 
 from logilab.common import attrdict
@@ -228,7 +228,7 @@
         """
         for cst in self.eschema.rdef(attrname).constraints:
             if isinstance(cst, StaticVocabularyConstraint):
-                return unicode(choice(cst.vocabulary()))
+                return text_type(choice(cst.vocabulary()))
         return None
 
     # XXX nothing to do here
@@ -353,7 +353,7 @@
                 fmt = vreg.property_value('ui.float-format')
                 value = fmt % value
             else:
-                value = unicode(value)
+                value = text_type(value)
     return entity