diff --git a/packages/frontend/src/filters/hms.ts b/packages/frontend/src/filters/hms.ts
index 64fd5a6496..b11313780b 100644
--- a/packages/frontend/src/filters/hms.ts
+++ b/packages/frontend/src/filters/hms.ts
@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 export default (ms: number, enableMs = false) => {
 	const res: string[] = [];