diff --git a/filenames.gypi b/filenames.gypi
index aadc1a092f..17d1b3597c 100644
--- a/filenames.gypi
+++ b/filenames.gypi
@@ -182,6 +182,9 @@
       'atom/browser/net/url_request_fetch_job.h',
       'atom/browser/node_debugger.cc',
       'atom/browser/node_debugger.h',
+      'atom/browser/process_singleton_posix.cc',
+      'atom/browser/process_singleton_startup_lock.cc',
+      'atom/browser/process_singleton_win.cc',
       'atom/browser/ui/accelerator_util.cc',
       'atom/browser/ui/accelerator_util.h',
       'atom/browser/ui/accelerator_util_mac.mm',