diff --git a/libs/canvas/canvas.cc b/libs/canvas/canvas.cc
index 54ce92d6dd..313c9f7ae5 100644
--- a/libs/canvas/canvas.cc
+++ b/libs/canvas/canvas.cc
@@ -195,9 +195,6 @@ Duple
 Canvas::canvas_to_window (Duple const & d) const
 {
 	Duple wd = d.translate (Duple (-_scroll_offset_x, -_scroll_offset_y));
-
-	/* Notice that this always return integer (pixel) values. */
-
 	wd.x = round (wd.x);
 	wd.y = round (wd.y);
 	return wd;
@@ -213,14 +210,10 @@ Rect
 Canvas::canvas_to_window (Rect const & r) const
 {
 	Rect wr = r.translate (Duple (-_scroll_offset_x, -_scroll_offset_y));
-
-	/* Notice that this always return integer (pixel) values. */
-
-	wr.x0 = round (wr.x0);
-	wr.x1 = round (wr.x1);
-	wr.y0 = round (wr.y0);
-	wr.y1 = round (wr.y1);
-
+	wr.x0 = floor (wr.x0);
+	wr.x1 = ceil (wr.x1);
+	wr.y0 = floor (wr.y0);
+	wr.y1 = ceil (wr.y1);
 	return wr;
 }