diff --git a/build/xtask/src/print.rs b/build/xtask/src/print.rs
index 048c120af..675feac6e 100644
--- a/build/xtask/src/print.rs
+++ b/build/xtask/src/print.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 std::path::Path;
 
 use anyhow::{bail, Context, Error, Result};