diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc
index 760ac6efb0..174a2d626a 100644
--- a/libs/canvas/rectangle.cc
+++ b/libs/canvas/rectangle.cc
@@ -288,12 +288,15 @@ Rectangle::vertical_fraction (double y) const
 void
 Rectangle::size_allocate (Rect const & r)
 {
-	/* leave position alone */
-
 	_allocation = r;
 
 	if (_layout_sensitive) {
-		set (r);
+		/* set position, and then set the _rect member with values that
+		   use _position as the origin.
+		*/
+		_position = Duple (r.x0, r.y0);
+		Rect r2 (0, 0, r.x1 - r.x0, r.y1 - r.y0);
+		set (r2);
 	}
 }
 
@@ -306,3 +309,4 @@ Rectangle::set_corner_radius (double r)
 	_corner_radius = r;
 	end_change ();
 }
+