$OpenBSD$
--- src/zmc.cpp.orig	Sat Apr  9 11:47:28 2016
+++ src/zmc.cpp	Sat Apr  9 11:47:36 2016
@@ -57,7 +57,7 @@ possible, this should run at more or less constant spe
 
 #include <getopt.h>
 #include <signal.h>
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
 #include <limits.h>
 #else
 #include <values.h>
