Index: src/mndp.c
--- src/mndp.c.orig
+++ src/mndp.c
@@ -26,6 +26,12 @@
 #include <net/ethernet.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
+#elif defined(__OpenBSD__)
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
 #else
 #include <netinet/ether.h>
 #endif