diff --git a/cf/sunos.m4 b/cf/sunos.m4
new file mode 100644
index 000000000..641381ee2
--- /dev/null
+++ b/cf/sunos.m4
@@ -0,0 +1,25 @@
+dnl
+dnl $Id$
+dnl
+
+AC_DEFUN([rk_SUNOS],[
+sunos=no
+case "$host" in 
+*-*-sunos4*)
+	sunos=40
+	;;
+*-*-solaris2.7)
+	sunos=57
+	;;
+*-*-solaris2.[89])
+	sunos=58
+	;;
+*-*-solaris2*)
+	sunos=50
+	;;
+esac
+if test "$sunos" != no; then
+	AC_DEFINE_UNQUOTED(SunOS, $sunos, 
+		[Define to what version of SunOS you are running.])
+fi
+])
\ No newline at end of file