diff --git a/update_engine.gyp b/update_engine.gyp
index c828a49..7a1ad95 100644
--- a/update_engine.gyp
+++ b/update_engine.gyp
@@ -189,6 +189,7 @@
         'payload_consumer/download_action.cc',
         'payload_consumer/extent_writer.cc',
         'payload_consumer/file_descriptor.cc',
+        'payload_consumer/file_descriptor_utils.cc',
         'payload_consumer/file_writer.cc',
         'payload_consumer/filesystem_verifier_action.cc',
         'payload_consumer/install_plan.cc',
@@ -532,6 +533,8 @@
             'payload_consumer/delta_performer_unittest.cc',
             'payload_consumer/download_action_unittest.cc',
             'payload_consumer/extent_writer_unittest.cc',
+            'payload_consumer/fake_file_descriptor.cc',
+            'payload_consumer/file_descriptor_utils_unittest.cc',
             'payload_consumer/file_writer_unittest.cc',
             'payload_consumer/filesystem_verifier_action_unittest.cc',
             'payload_consumer/postinstall_runner_action_unittest.cc',