$OpenBSD: patch-include_private_gc_priv_h,v 1.1 2013/06/01 21:05:28 kurt Exp $
--- include/private/gc_priv.h.orig	Thu Aug  9 16:25:13 2012
+++ include/private/gc_priv.h	Tue Mar 19 19:39:39 2013
@@ -2209,7 +2209,11 @@ GC_INNER ptr_t GC_store_debug_info(ptr_t p, word sz, c
       /* Linuxthreads itself uses SIGUSR1 and SIGUSR2.                  */
 #     define SIG_SUSPEND SIGPWR
 #   endif
-# elif !defined(GC_OPENBSD_THREADS) && !defined(GC_DARWIN_THREADS)
+# elif defined(GC_OPENBSD_THREADS)
+#   if OpenBSD >= 201211
+#     define SIG_SUSPEND SIGXFSZ
+#   endif
+# elif !defined(GC_DARWIN_THREADS)
 #   if defined(_SIGRTMIN)
 #     define SIG_SUSPEND _SIGRTMIN + 6
 #   else
