diff --git a/Data/PrimitiveArray/Zero.hs b/Data/PrimitiveArray/Zero.hs
--- a/Data/PrimitiveArray/Zero.hs
+++ b/Data/PrimitiveArray/Zero.hs
@@ -35,7 +35,7 @@
 -- NOTE inLb, inUb is including bound, while exUb is excluding upper bound.
 -- Differentiates between largest included index, first excluded index.
 
-instance (Shape sh, ExtShape sh, Prim elm) => MPrimArrayOps MArr0 sh elm where
+instance (Shape sh, ExtShape sh) => MPrimArrayOps MArr0 sh elm where
   boundsM (MArr0 exUb _) = (zeroDim,exUb `subDim` unitDim)
   fromListM inLb inUb xs = do
     ma <- newM inLb inUb
@@ -61,7 +61,7 @@
   {-# INLINE readM #-}
   {-# INLINE writeM #-}
 
-instance (Shape sh, ExtShape sh, Prim elm) => PrimArrayOps Arr0 sh elm where
+instance (Shape sh, ExtShape sh) => PrimArrayOps Arr0 sh elm where
   bounds (Arr0 exUb _) = (zeroDim,exUb `subDim` unitDim)
   freeze (MArr0 exUb mba) = Arr0 exUb `liftM` unsafeFreezeArray mba
   index (Arr0 exUb ba) idx = assert (inShape exUb idx) $ indexArray ba (toIndex exUb idx)
diff --git a/PrimitiveArray.cabal b/PrimitiveArray.cabal
--- a/PrimitiveArray.cabal
+++ b/PrimitiveArray.cabal
@@ -1,5 +1,5 @@
 Name:           PrimitiveArray
-Version:        0.2.1.0
+Version:        0.2.1.1
 License:        BSD3
 License-file:   LICENSE
 Author:         Christian Hoener zu Siederdissen