diff --git a/packages/frontend/src/types/option-value.ts b/packages/frontend/src/types/option-value.ts
index 6794f8a583..98d0fb5faa 100644
--- a/packages/frontend/src/types/option-value.ts
+++ b/packages/frontend/src/types/option-value.ts
@@ -1 +1,6 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 export type OptionValue = string | number | null;