Index: include/u.h
===================================================================
--- include/u.h.orig
+++ include/u.h
@@ -38,9 +38,12 @@ extern "C" {
 #		define __MAKECONTEXT_V2_SOURCE 1
 #	endif
 #endif
+#if defined __linux__ || defined __GNU__ || defined __GLIBC__
+#define _DEFAULT_SOURCE 1
+#else
 #define _BSD_SOURCE 1
-#define _NETBSD_SOURCE 1	/* NetBSD */
 #define _SVID_SOURCE 1
+#endif
 #if !defined(__APPLE__) && !defined(__OpenBSD__)
 #	define _XOPEN_SOURCE 1000
 #	define _XOPEN_SOURCE_EXTENDED 1