diff --git a/phd-tests/runner/build.rs b/phd-tests/runner/build.rs
index c035cdecb..46b0bab40 100644
--- a/phd-tests/runner/build.rs
+++ b/phd-tests/runner/build.rs
@@ -1,3 +1,7 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use anyhow::Context;
 
 fn main() -> anyhow::Result<()> {