$OpenBSD$
--- build/platform_specific.mk.orig	Mon Nov 29 19:46:35 2010
+++ build/platform_specific.mk	Thu Dec  2 01:52:08 2010
@@ -51,14 +51,20 @@ ifeq ($(TARGET_OS),linux-gnu)
 #	-Wunsafe-loop-optimizations
 endif
 
-# FreeBSD like
+# FreeBSD
 ifeq ($(TARGET_OS),freebsd)
 	CFLAGS+=-D_BSD_SOURCE -D_XOPEN_SOURCE
 	LDFLAGS+=-lexecinfo
 endif
 
+# NetBSD
 ifeq ($(TARGET_OS),netbsd)
 	CFLAGS+=-D_BSD_SOURCE -D_NETBSD_SOURCE
+endif
+
+# OpenBSD
+ifeq ($(TARGET_OS),OpenBSD)
+	CFLAGS+=-D_BSD_SOURCE
 endif
 
 # Darwin