Use unicode for reference (is there any way to build this module)
diff --git a/Modules/xxmodule.c b/Modules/xxmodule.c
index 0923f81..7509e20 100644
--- a/Modules/xxmodule.c
+++ b/Modules/xxmodule.c
@@ -246,7 +246,7 @@
 	0,			/*tp_methods*/
 	0,			/*tp_members*/
 	0,			/*tp_getset*/
-	&PyString_Type,		/*tp_base*/
+	&PyUnicode_Type,	/*tp_base*/
 	0,			/*tp_dict*/
 	0,			/*tp_descr_get*/
 	0,			/*tp_descr_set*/