$OpenBSD$
--- src/threads/native/threads.h.orig	Mon Feb 13 18:14:32 2006
+++ src/threads/native/threads.h	Mon Apr 10 07:56:57 2006
@@ -40,7 +40,10 @@
 
 #include <pthread.h>
 #include <semaphore.h>
+
+#ifndef __OPENBSD__
 #include <ucontext.h>
+#endif
 
 #include "vm/types.h"
 
