diff --git a/server/src/server/router/ir/beatoraja/auth.ts b/server/src/server/router/ir/beatoraja/auth.ts
index f9c2c581b..06337c7b5 100644
--- a/server/src/server/router/ir/beatoraja/auth.ts
+++ b/server/src/server/router/ir/beatoraja/auth.ts
@@ -3,5 +3,12 @@ import { RequestHandler } from "express";
 export const ValidateIRClientVersion: RequestHandler = (req, res, next) => {
 	const header = req.header("X-TachiIR-Version");
 
+	if (!header?.startsWith("v2")) {
+		return res.status(400).json({
+			success: false,
+			description: `Invalid X-TachiIR-Version.`,
+		});
+	}
+
 	return next();
 };