diff -Naur argtable2-13/src/arg_int.c argtable2-13-mod/src/arg_int.c
--- argtable2-13/src/arg_int.c	2023-09-27 02:23:18.210986500 -0600
+++ argtable2-13-mod/src/arg_int.c	2023-09-27 02:17:04.986336900 -0600
@@ -30,6 +30,7 @@
 
 #include "argtable2.h"
 #include <limits.h>
+#include <ctype.h>
 
 /* local error codes */
 enum {EMINCOUNT=1,EMAXCOUNT,EBADINT,MYEOVERFLOW};
