diff -r a62072cf50a2 Tools/clinic/clinic.py
--- a/Tools/clinic/clinic.py	Wed Jan 22 12:26:01 2014 +0100
+++ b/Tools/clinic/clinic.py	Wed Jan 22 18:41:05 2014 +0200
@@ -777,7 +777,7 @@
                 return_value_declaration = "int return_value = -1;"
                 parser_prototype = templates['parser_prototype_init']
 
-            fields = list(parser_body_fields)
+            fields = list(parser_body_fields) if parser_body_fields is not None else []
             parses_positional = 'METH_NOARGS' not in flags
             parses_keywords = 'METH_KEYWORDS' in flags
             if parses_keywords: