diff --git a/geometry.go b/geometry.go
index 0cb1436..5f16ba4 100644
--- a/geometry.go
+++ b/geometry.go
@@ -310,7 +310,7 @@ func (r Rect) Intersect(s Rect) Rect {
 	return t
 }
 
-// Matrix is a 3x2 affine matrix that can be used for all kinds of spatial transforms, such
+// Matrix is a 2x3 affine matrix that can be used for all kinds of spatial transforms, such
 // as movement, scaling and rotations.
 //
 // Matrix has a handful of useful methods, each of which adds a transformation to the matrix. For