diff --git a/gtk2_ardour/wscript b/gtk2_ardour/wscript
index f9491f686a..00edab5d24 100644
--- a/gtk2_ardour/wscript
+++ b/gtk2_ardour/wscript
@@ -297,6 +297,7 @@ gtk2_ardour_sources = [
         'transport_control_ui.cc',
         'transport_masters_dialog.cc',
         'transpose_dialog.cc',
+        'trigger_ui.cc',
         'triggerbox_ui.cc',
         'ui_config.cc',
         'utils.cc',