diff --git a/geometry.go b/geometry.go
index 207ab27..b55d13b 100644
--- a/geometry.go
+++ b/geometry.go
@@ -255,7 +255,7 @@ func (r Rect) Union(s Rect) Rect {
 // Matrix has a handful of useful methods, each of which adds a transformation to the matrix. For
 // example:
 //
-//   pixel.IM.Moved(pixel.V(100, 200)).Rotated(0, math.Pi/2)
+//   pixel.IM.Moved(pixel.V(100, 200)).Rotated(pixel.ZV, math.Pi/2)
 //
 // This code creates a Matrix that first moves everything by 100 units horizontally and 200 units
 // vertically and then rotates everything by 90 degrees around the origin.