--- a/gtk/meson.build	2022-02-18 21:58:42.158880825 +0900
+++ b/gtk/meson.build	2022-02-18 22:17:13.959003252 +0900
@@ -17,6 +17,7 @@
 
 # List of sources to build the library from
 gtk_sources = files(
+  'ubuntumenuitemfactory.c',
   'gtkactionmuxer.c',
   'gtkactionobserver.c',
   'gtkactionobservable.c',
--- a/gtk/meson.build	2022-02-18 21:25:46.058931885 +0900
+++ b/gtk/meson.build	2022-02-18 21:51:15.638021535 +0900
@@ -396,6 +396,8 @@
   'gtk.h',
   'gtk-autocleanups.h',
   'gtkx-autocleanups.h',
+  'ubuntu-private.h',
+  'ubuntumenuitemfactory.h',
   'gtk-a11y.h',
   'gtkaboutdialog.h',
   'gtkaccelgroup.h',