diff --git a/packages/backend/src/misc/FileWriterStream.ts b/packages/backend/src/misc/FileWriterStream.ts
index 828851df0..367a8eb56 100644
--- a/packages/backend/src/misc/FileWriterStream.ts
+++ b/packages/backend/src/misc/FileWriterStream.ts
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 import * as fs from 'node:fs/promises';
 import type { PathLike } from 'node:fs';
 
diff --git a/packages/backend/src/misc/JsonArrayStream.ts b/packages/backend/src/misc/JsonArrayStream.ts
index ad35bb3a7..754938989 100644
--- a/packages/backend/src/misc/JsonArrayStream.ts
+++ b/packages/backend/src/misc/JsonArrayStream.ts
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 import { TransformStream } from 'node:stream/web';
 
 /**
diff --git a/packages/frontend/src/scripts/search-emoji.ts b/packages/frontend/src/scripts/search-emoji.ts
index 07f55e553..371f69b9a 100644
--- a/packages/frontend/src/scripts/search-emoji.ts
+++ b/packages/frontend/src/scripts/search-emoji.ts
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 export type EmojiDef = {
 	emoji: string;
 	name: string;