diff --git a/packages/backend/src/server/web/views/flush.pug b/packages/backend/src/server/web/views/flush.pug
index 1d138572d0..7884495d08 100644
--- a/packages/backend/src/server/web/views/flush.pug
+++ b/packages/backend/src/server/web/views/flush.pug
@@ -6,7 +6,7 @@ html
 		const msg = document.getElementById('msg');
 		const successText = `\nSuccess Flush! <a href="/">Back to Misskey</a>\n成功しました。<a href="/">Misskeyを開き直してください。</a>`;
 
-		if (!document.cookie.includes('http-flush-failed=1')) {
+		if (!document.cookie) {
 			message('Your site data is fully cleared by your browser.');
 			message(successText);
 		} else {