diff --git a/lib/ex_unit.ex b/lib/ex_unit.ex
index 327ebf2..6f67dbc 100644
--- a/lib/ex_unit.ex
+++ b/lib/ex_unit.ex
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
 defmodule TestcontainersElixir.ExUnit do
 
   alias TestcontainersElixir.Reaper