diff --git a/packages/backend/src/@types/twemoji.d.ts b/packages/backend/src/@types/twemoji.d.ts
index 6ba7462e6e..8574f103ed 100644
--- a/packages/backend/src/@types/twemoji.d.ts
+++ b/packages/backend/src/@types/twemoji.d.ts
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 declare module '@twemoji/parser/dist/lib/regex' {
 	const regex: RegExp;
 	export default { default: regex };