--- pyconfig.h.in.orig	Sun Nov 10 07:36:41 2013
+++ pyconfig.h.in	Fri Apr 18 17:38:30 2014
@@ -1197,7 +1197,9 @@
 #undef _UINT64_T
 
 /* Define to the level of X/Open that your system supports */
+#if !defined(__sun) || (defined(__sun) && !defined(_XOPEN_SOURCE))
 #undef _XOPEN_SOURCE
+#endif
 
 /* Define to activate Unix95-and-earlier features */
 #undef _XOPEN_SOURCE_EXTENDED