diff --git a/Math/Manifold/VectorSpace/ZeroDimensional.hs b/Math/Manifold/VectorSpace/ZeroDimensional.hs
--- a/Math/Manifold/VectorSpace/ZeroDimensional.hs
+++ b/Math/Manifold/VectorSpace/ZeroDimensional.hs
@@ -20,7 +20,7 @@
 
 
 
-data ZeroDim s = Origin
+data ZeroDim s = Origin deriving (Eq, Show)
 
 instance Monoid (ZeroDim s) where
   mempty = Origin
@@ -42,3 +42,6 @@
   basisValue = absurd
   decompose Origin = []
   decompose' Origin = absurd
+instance (AdditiveGroup s) => InnerSpace (ZeroDim s) where
+  Origin <.> Origin = zeroV
+
diff --git a/manifolds-core.cabal b/manifolds-core.cabal
--- a/manifolds-core.cabal
+++ b/manifolds-core.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                manifolds-core
-version:             0.4.0.0
+version:             0.4.1.0
 synopsis:            The basic classes for the manifolds hierarchy.
 description:         The basic classes for the
                      <http://hackage.haskell.org/package/manifolds manifolds> hierarchy.