diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index c49885524b..33efcbdc5a 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -544,7 +544,7 @@ Editor::maybe_autoscroll (bool allow_horiz, bool allow_vert)
 	framepos_t rightmost_frame = leftmost_frame + current_page_frames();
 	bool startit = false;
 
-	double ty = _drags->current_pointer_y() - get_trackview_group_vertical_offset ();
+	double const ty = _drags->current_pointer_y() - get_trackview_group_vertical_offset ();
 
 	autoscroll_y = 0;
 	autoscroll_x = 0;
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index fa27f5c45c..341b023c12 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -352,9 +352,9 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible {
 #endif
 
 	virtual gdouble get_trackview_group_vertical_offset () const = 0;
-	virtual gdouble get_canvas_timebars_vsize () const = 0;
-	virtual ArdourCanvas::Group* get_background_group () const = 0;
+	virtual double get_canvas_timebars_vsize () const = 0;
 	virtual ArdourCanvas::Group* get_trackview_group () const = 0;
+	virtual ArdourCanvas::Group* get_background_group () const = 0;
 
 	virtual TimeAxisView* axis_view_from_route (boost::shared_ptr<ARDOUR::Route>) const = 0;
 
diff --git a/gtk2_ardour/time_axis_view.cc b/gtk2_ardour/time_axis_view.cc
index 2022783928..b93831f69f 100644
--- a/gtk2_ardour/time_axis_view.cc
+++ b/gtk2_ardour/time_axis_view.cc
@@ -1230,14 +1230,14 @@ TimeAxisView::resizer_motion (GdkEventMotion* ev)
 {
 	if (_resize_drag_start >= 0) {
 		/* (ab)use the DragManager to do autoscrolling; adjust the event coordinates
-		   into the trackview space that DragManager::motion_handler is expecting,
+		   into the world coordinate space that DragManager::motion_handler is expecting,
 		   and then fake a DragManager motion event so that when maybe_autoscroll
 		   asks DragManager for the current pointer position it will get the correct
 		   answers.
 		*/
 		int tx, ty;
 		resizer.translate_coordinates (*control_parent, ev->x, ev->y, tx, ty);
-		ev->y = ty + _editor.get_canvas_timebars_vsize ();
+		ev->y = ty - _editor.get_trackview_group_vertical_offset();
 		_editor.drags()->motion_handler ((GdkEvent *) ev, false);
 		_editor.maybe_autoscroll (false, true);