diff --git a/tools/command.c b/tools/command.c
index 8198c5f3a..20b1811f8 100644
--- a/tools/command.c
+++ b/tools/command.c
@@ -941,12 +941,28 @@ static void _add_opt_arg(struct command *cmd, char *str,
 	}
 
 skip:
-	if (required > 0)
+	if (required > 0) {
+		if (cmd->ro_count >= CMD_RO_ARGS) {
+			log_error("Too many args, increase CMD_RO_ARGS.");
+			cmd->cmd_flags |= CMD_FLAG_PARSE_ERROR;
+			return;
+		}
 		cmd->required_opt_args[cmd->ro_count++].opt = opt;
-	else if (!required)
+	} else if (!required) {
+		if (cmd->oo_count >= CMD_OO_ARGS) {
+			log_error("Too many args, increase CMD_OO_ARGS.");
+			cmd->cmd_flags |= CMD_FLAG_PARSE_ERROR;
+			return;
+		}
 		cmd->optional_opt_args[cmd->oo_count++].opt = opt;
-	else if (required < 0)
+	} else if (required < 0) {
+		if (cmd->io_count >= CMD_IO_ARGS) {
+			log_error("Too many args, increase CMD_IO_ARGS.");
+			cmd->cmd_flags |= CMD_FLAG_PARSE_ERROR;
+			return;
+		}
 		cmd->ignore_opt_args[cmd->io_count++].opt = opt;
+	}
 
 	*takes_arg = opt_names[opt].val_enum ? 1 : 0;
 }
diff --git a/tools/command.h b/tools/command.h
index 72391e45c..3497b1fe4 100644
--- a/tools/command.h
+++ b/tools/command.h
@@ -152,12 +152,12 @@ struct cmd_rule {
  * of which one is required after which the rest are
  * optional.
  */
-#define CMD_RO_ARGS 64          /* required opt args */
-#define CMD_OO_ARGS 100         /* optional opt args */
+#define CMD_RO_ARGS 32          /* required opt args */
+#define CMD_OO_ARGS 64          /* optional opt args */
 #define CMD_RP_ARGS 8           /* required positional args */
 #define CMD_OP_ARGS 8           /* optional positional args */
 #define CMD_IO_ARGS 8           /* ignore opt args */
-#define CMD_MAX_RULES 32        /* max number of rules per command def */
+#define CMD_MAX_RULES 16        /* max number of rules per command def */
 
 /*
  * one or more from required_opt_args is required,