diff --git a/src/components/script/style/tests/mod.rs b/src/components/script/style/tests/mod.rs
index a39c7114439..8c2771a9a0a 100644
--- a/src/components/script/style/tests/mod.rs
+++ b/src/components/script/style/tests/mod.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 http://mozilla.org/MPL/2.0/. */
+
 use super::stylesheets::parse_stylesheet;
 
 #[test]