$NetBSD: patch-ac,v 1.6 2005/12/30 14:18:52 joerg Exp $

--- gc/include/gc_config_macros.h.orig	2005-12-30 13:35:00.000000000 +0000
+++ gc/include/gc_config_macros.h
@@ -87,7 +87,7 @@
 #   define GC_DARWIN_THREADS
 #   define GC_PTHREADS
 # endif
-# if !defined(GC_PTHREADS) && defined(__FreeBSD__)
+# if !defined(GC_PTHREADS) && (defined(__FreeBSD__) || defined(__DragonFly__))
 #   define GC_FREEBSD_THREADS
 #   define GC_PTHREADS
 # endif
