diff --git a/Graphics/DrawingCombinators/Affine.hs b/Graphics/DrawingCombinators/Affine.hs
--- a/Graphics/DrawingCombinators/Affine.hs
+++ b/Graphics/DrawingCombinators/Affine.hs
@@ -56,8 +56,8 @@
 -- undefined.
 inverse :: Affine -> Affine
 inverse (M x11 x12 x13 x21 x22 x23) = 
-    M (s*x22)   (-s*x12)  (s*x22 *x13 - s*x12*x23)
-      (-s*x21)  (s*x11)   (-s*x21*x13 + s*x11*x23)
+    M (s*x22)   (-s*x12)  (-s*x22*x13 + s*x12*x23)
+      (-s*x21)  (s*x11)   ( s*x21*x13 - s*x11*x23)
     where
     s = 1 / (x11*x22 - x12*x21)
 
diff --git a/graphics-drawingcombinators.cabal b/graphics-drawingcombinators.cabal
--- a/graphics-drawingcombinators.cabal
+++ b/graphics-drawingcombinators.cabal
@@ -4,7 +4,7 @@
     have to go into the deep, dark world of imperative stateful
     programming just to draw stuff.  It supports 2D only (for now),
     with support drawing geometry, images, and text.
-Version: 1.3.0
+Version: 1.3.1
 Stability: experimental
 Synopsis: A functional interface to 2D drawing in OpenGL
 License: BSD3