diff --git a/primes-type.cabal b/primes-type.cabal
--- a/primes-type.cabal
+++ b/primes-type.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           primes-type
-version:        0.2.0.2
+version:        0.2.0.3
 synopsis:       Type-safe prime numbers.
 description:    This library provides type safe prime numbers. The idea is based upon the concept of a predicate type from type theory.
 category:       Algorithms, Numerical
diff --git a/src/Data/Numbers/Primes/Type.hs b/src/Data/Numbers/Primes/Type.hs
--- a/src/Data/Numbers/Primes/Type.hs
+++ b/src/Data/Numbers/Primes/Type.hs
@@ -46,9 +46,7 @@
     x `compare` y = getIndex x `compare` getIndex y
 
 deriving instance Generic (Prime a)
-deriving instance Generic1 Prime
 instance NFData a => NFData (Prime a)
-instance NFData1 Prime
 
 -- | If a given number is prime, give back its index.
 primeIndex :: Integral n => n -> Maybe Int