diff --git a/geometry.go b/geometry.go
index 0cb143665a1f17c5571d376f9d32c52511c9e25f..5f16ba45355c3d9cb6faa66322011ec6e18d7188 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