Changed to use 'U' argument to PyArg_ParseTuple, instead of manually checking for unicode objects.
diff --git a/Objects/stringlib/stringdefs.h b/Objects/stringlib/stringdefs.h
index af9bbd6..a4be17f 100644
--- a/Objects/stringlib/stringdefs.h
+++ b/Objects/stringlib/stringdefs.h
@@ -8,6 +8,7 @@
 
 #define STRINGLIB_CHAR           char
 #define STRINGLIB_TYPE_NAME      "string"
+#define STRINGLIB_PARSE_CODE     "S"
 #define STRINGLIB_EMPTY          string_empty
 #define STRINGLIB_ISDECIMAL(x)   ((x >= '0') && (x <= '9'))
 #define STRINGLIB_TODECIMAL(x)   (STRINGLIB_ISDECIMAL(x) ? (x - '0') : -1)