diff --git a/src/server/api/private/signin.ts b/src/server/api/private/signin.ts
index 0e44c2ddd6..0a0f9ae6f9 100644
--- a/src/server/api/private/signin.ts
+++ b/src/server/api/private/signin.ts
@@ -12,9 +12,8 @@ export default async (ctx: Koa.Context) => {
 	ctx.set('Access-Control-Allow-Credentials', 'true');
 
 	const body = ctx.request.body as any;
-	// See: https://github.com/syuilo/misskey/issues/2384
-	const username = body['username'] || body['x'];
-	const password = body['password'] || body['y'];
+	const username = body['username'];
+	const password = body['password'];
 	const token = body['token'];
 
 	if (typeof username != 'string') {