diff --git a/distrib/msw/tmake/filelist.txt b/distrib/msw/tmake/filelist.txt
index 2a29c3cd2b..6a9da4d8ad 100644
--- a/distrib/msw/tmake/filelist.txt
+++ b/distrib/msw/tmake/filelist.txt
@@ -952,6 +952,7 @@ textdlg.h	WXH
 textfile.h	WXH	Base
 tglbtn.h	WXH
 thread.h	WXH	Base
+thrimpl.cpp	WXH	Base
 time.h	WXH	Base
 timer.h	WXH	Base
 tipdlg.h	WXH