$OpenBSD$
--- xl2tpd.c.orig	Fri May 22 13:41:16 2009
+++ xl2tpd.c	Fri May 22 13:42:01 2009
@@ -31,6 +31,7 @@
 #if (__GLIBC__ < 2)
 # if defined(FREEBSD) || defined(OPENBSD)
 #  include <sys/signal.h>
+#  include <signal.h>
 # elif defined(LINUX)
 #  include <bsd/signal.h>
 # elif defined(SOLARIS)