diff --git a/appl/rsh/rsh_locl.h b/appl/rsh/rsh_locl.h
index bd12c6d35..a2cb298cd 100644
--- a/appl/rsh/rsh_locl.h
+++ b/appl/rsh/rsh_locl.h
@@ -145,10 +145,9 @@ extern des_cblock iv;
 #define KCMD_NEW_VERSION "KCMDV0.2"
 
 #define USERNAME_SZ 16
-#ifndef NCARGS
-#define NCARGS 8192
+#ifndef ARG_MAX
+#define ARG_MAX 8192
 #endif
-#define COMMAND_SZ (NCARGS+1)
 
 #define RSH_BUFSIZ (5 * 1024) /* MIT kcmd can't handle larger buffers */