--- bc-2.5.1/include/args.h.orig	Fri Jan 24 19:27:06 2020
+++ bc-2.5.1/include/args.h	Fri Jan 24 19:27:14 2020
@@ -36,6 +36,8 @@
 #ifndef BC_ARGS_H
 #define BC_ARGS_H
 
+#include <getopt.h>
+
 #include <status.h>
 #include <vm.h>