diff --git a/tb/pmd.py b/tb/pmd.py
index 52f7cd1..2708fd6 100644
--- a/tb/pmd.py
+++ b/tb/pmd.py
@@ -1,3 +1,6 @@
+# SPDX-License-Identifier: AGPL-3.0-Only
+# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
+
 import random
 from statistics import NormalDist