diff --git a/gtk2_ardour/playlist_selector.h b/gtk2_ardour/playlist_selector.h
index 071f82c616..757e7fc523 100644
--- a/gtk2_ardour/playlist_selector.h
+++ b/gtk2_ardour/playlist_selector.h
@@ -28,7 +28,7 @@
 #include <gtkmm/treeview.h>
 #include <gtkmm2ext/selector.h>
 
-#include <ardour_dialog.h>
+#include "ardour_dialog.h"
 
 namespace ARDOUR {
 	class Session;
diff --git a/gtk2_ardour/plugin_ui.h b/gtk2_ardour/plugin_ui.h
index 17d643f2a1..5a712636f6 100644
--- a/gtk2_ardour/plugin_ui.h
+++ b/gtk2_ardour/plugin_ui.h
@@ -39,9 +39,9 @@
 #include <gtkmm/comboboxtext.h>
 #include <gtkmm/socket.h>
 
-#include <ardour_dialog.h>
 #include <ardour/types.h>
 
+#include "ardour_dialog.h"
 #include "latency_gui.h"
 #include "automation_controller.h"
 
diff --git a/gtk2_ardour/x11.cc b/gtk2_ardour/x11.cc
index 330d459abc..b5908341df 100644
--- a/gtk2_ardour/x11.cc
+++ b/gtk2_ardour/x11.cc
@@ -1,4 +1,4 @@
-#include <ardour_ui.h>
+#include "ardour_ui.h"
 
 void
 ARDOUR_UI::platform_specific ()