--- a/devtools/testlib.py	Fri Jun 26 16:29:28 2015 +0200
+++ b/devtools/testlib.py	Fri Jun 26 16:28:56 2015 +0200
@@ -724,7 +724,7 @@
             if entity_fields:
                 form[eid_param('_cw_entity_fields', entity.eid)] = ','.join(entity_fields)
         if fields:
-            form['_cw_fields'] = ','.join(fields)
+            form['_cw_fields'] = ','.join(sorted(fields))
         return form
 
     @deprecated('[3.19] use .admin_request_from_url instead')