diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index 4f237c7c94..4d6f7119cc 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -29,7 +29,6 @@
 
 #include <gtkmm2ext/gtk_ui.h>
 #include <gtkmm2ext/utils.h>
-#include <gtkmm2ext/stop_signal.h>
 #include <gtkmm2ext/tearoff.h>
 #include <gtkmm2ext/window_title.h>