diff --git a/src/TypeUnary/Vec.hs b/src/TypeUnary/Vec.hs
--- a/src/TypeUnary/Vec.hs
+++ b/src/TypeUnary/Vec.hs
@@ -54,6 +54,8 @@
 import Foreign.Storable
 import Foreign.Ptr (Ptr,plusPtr,castPtr)
 
+import Control.Newtype (Newtype(..))
+
 import Data.VectorSpace
 
 import TypeUnary.Nat
@@ -211,6 +213,13 @@
   traverse _ ZVec      = pure ZVec
   traverse f (a :< as) = liftA2 (:<) (f a) (traverse f as)
 
+instance Newtype (Vec Z a) () where
+  pack () = ZVec
+  unpack ZVec = ()
+
+instance Newtype (Vec (S n) a) (a,Vec n a) where
+  pack = uncurry (:<)
+  unpack = unConsV
 
 instance (IsNat n, Num a) => AdditiveGroup (Vec n a) where
   { zeroV = pure 0; (^+^) = liftA2 (+) ; negateV = fmap negate }
diff --git a/type-unary.cabal b/type-unary.cabal
--- a/type-unary.cabal
+++ b/type-unary.cabal
@@ -1,5 +1,5 @@
 Name:                type-unary
-Version:             0.2.14
+Version:             0.2.15
 Cabal-Version:       >= 1.6
 Synopsis:            
   Type-level and typed unary natural numbers, inequality proofs, vectors
@@ -25,7 +25,11 @@
 Library
   hs-Source-Dirs:      src
   Extensions:
-  Build-Depends:       base >=4 && < 5, ty>=0.1.5, vector-space, applicative-numbers
+  Build-Depends:       base >=4 && < 5
+                     , newtype >= 0.2
+                     , ty >= 0.1.5
+                     , vector-space
+                     , applicative-numbers
   Exposed-Modules:     
                        TypeUnary.TyNat
                        TypeUnary.Nat