diff --git a/update_engine.gyp b/update_engine.gyp
index e2a8de0..6138b87 100644
--- a/update_engine.gyp
+++ b/update_engine.gyp
@@ -189,6 +189,7 @@
         'payload_constants.cc',
         'payload_state.cc',
         'payload_verifier.cc',
+        'platform_constants_chromeos.cc',
         'postinstall_runner_action.cc',
         'prefs.cc',
         'proxy_resolver.cc',