diff --git a/libs/widgets/tabbable.cc b/libs/widgets/tabbable.cc
index 2082332a84..482fd1fe85 100644
--- a/libs/widgets/tabbable.cc
+++ b/libs/widgets/tabbable.cc
@@ -125,7 +125,9 @@ Tabbable::default_layout ()
 		content_left_pane.add (content_att_left);
 		content_left_pane.add (content_midlevel_vbox);
 	} else {
-		_content_vbox.pack_start (content_midlevel_vbox, true, true);
+		_content_vbox.pack_start (content_hbox, true, true);
+		content_hbox.pack_start (content_att_left, false, false);
+		content_hbox.pack_start (content_midlevel_vbox, true, true);
 	}
 
 	if (_panelayout & PaneRight) {
@@ -137,20 +139,21 @@ Tabbable::default_layout ()
 		content_midlevel_vbox.pack_start (content_inner_hbox, true, true);
 	}
 
+	content_main_vbox.pack_start (content_main_top, false, false);
+	content_main_vbox.pack_start (content_main, true, true);
+
 	if (_panelayout & PaneBottom) {
 		content_inner_hbox.pack_start (content_bottom_pane, true, true);
 		content_bottom_pane.add (content_main_vbox);
 		content_bottom_pane.add (content_att_bottom);
 	} else {
 		content_inner_hbox.pack_start (content_main_vbox, true, true);
+		content_main_vbox.pack_start (content_att_bottom, false, false);
 	}
 
 	content_inner_hbox.pack_start (content_bus_vbox, false, false);
 	content_bus_vbox.pack_start (content_bus, true, true);
 
-	content_main_vbox.pack_start (content_main_top, false, false);
-	content_main_vbox.pack_start (content_main, true, true);
-
 	/* set pane min. sizes */
 
 	if (_panelayout & PaneRight) {
diff --git a/libs/widgets/widgets/tabbable.h b/libs/widgets/widgets/tabbable.h
index 0ef5806994..ecf755a373 100644
--- a/libs/widgets/widgets/tabbable.h
+++ b/libs/widgets/widgets/tabbable.h
@@ -131,7 +131,7 @@ protected:
 	 * | | +----------------------------------------------------------------------------------------------------------------------+ | |
 	 * | \--------------------------------------------------------------------------------------------------------------------------/ |
 	 * |                                                                                                                              |
-	 * | +--content_left_pane-(OPTIONAL)--------------------------------------------------------------------------------------------+ |
+	 * | +--content_hbox--OR--content_left_pane--(EXPAND|FILL)----------------------------------------------------------------------+ |
 	 * | |                                                                                                                          | |
 	 * | | +--att_left--+   +--content_midlevel_vbox------------------------------------------------------------------------------+ | |
 	 * | | $     (EBOX) |   | +--content_right_pane--(EXPAND|FILL)--------------------------------------------------------------+ | | |
@@ -177,6 +177,7 @@ protected:
 	Gtk::HBox           content_attachment_hbox;
 	EventBoxExt       content_tabbables;         /* a placeholder for the tabbable switching buttons (used by ArdourUI) */
 	HPane           content_left_pane;
+	Gtk::HBox       content_hbox;
 	EventBoxExt       content_att_left;          /* a placeholder for the mixer strip, if you want one */
 	Gtk::VBox         content_midlevel_vbox;
 	HPane               content_right_pane;