diff --git a/diff.py b/diff.py
index 267a55d..fd08fe6 100755
--- a/diff.py
+++ b/diff.py
@@ -1,5 +1,9 @@
 #!/usr/bin/env python3
 # PYTHON_ARGCOMPLETE_OK
+
+# SPDX-FileCopyrightText: 2019-2024 asm-differ contributors
+# SPDX-License-Identifier: Unlicense
+
 import argparse
 import enum
 import sys
diff --git a/test.py b/test.py
index d36ea8d..0367746 100644
--- a/test.py
+++ b/test.py
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2023-2024 asm-differ contributors
+# SPDX-License-Identifier: Unlicense
+
 import unittest
 import diff
 import json