diff --git a/src/expat-sys/debian/copyright b/src/expat-sys/debian/copyright
index fb1e7d0..7374c91 100644
--- a/src/expat-sys/debian/copyright
+++ b/src/expat-sys/debian/copyright
@@ -10,6 +10,20 @@
  2014—2015 Jack Moffitt
            and others
 License: MIT
+
+Files: build.rs
+Copyright:
+ 2013—2018 The Servo Project Developers
+ 2013      Yongjin Kim
+ 2014—2015 Jack Moffitt
+           and others
+License: MPL-2.0
+ 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/.
+ .
+ On Debian systems, the text of this license can be found at:
+ </usr/share/common-licenses/MPL-2.0>.
 
 Files: debian/*
 Copyright: