diff -r 7dd84b69c7d4 -r 23a2fa8cb725 entities/adapters.py
--- a/entities/adapters.py	Fri Jun 26 14:04:16 2015 +0200
+++ b/entities/adapters.py	Fri Jun 26 13:04:25 2015 +0200
@@ -143,7 +143,7 @@
                 continue
             weight = self.attr_weight.get(rschema, 'C')
             try:
-                value = entity.printable_value(rschema, format='text/plain')
+                value = entity.printable_value(rschema, format=u'text/plain')
             except TransformError:
                 continue
             except Exception: