--- boost-coroutine.orig/boost/coroutine/detail/context_posix.hpp
+++ boost-coroutine/boost/coroutine/detail/context_posix.hpp
@@ -46,13 +46,10 @@
 #include <boost/config.hpp>
 #include <boost/assert.hpp>
 
-#if defined(_XOPEN_UNIX) && defined(_XOPEN_VERSION) && _XOPEN_VERSION >= 500
+#if 1
+#if 1
 
-// OS X 10.4 -- despite passing the test above -- doesn't support
-// swapcontext() et al. Use GNU Pth workalike functions.
-#if defined(__APPLE__) && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1050)
-
-#include "pth/pth.h"
+#include <pth.h>
 #include <cerrno>
 
 namespace boost { namespace coroutines { namespace detail {