diff --git a/secp256k1.cabal b/secp256k1.cabal
--- a/secp256k1.cabal
+++ b/secp256k1.cabal
@@ -1,5 +1,5 @@
 name:                secp256k1
-version:             0.1.3
+version:             0.1.4
 synopsis:            secp256k1 bindings for Haskell
 description:         Please see README.md
 homepage:            http://github.com/haskoin/secp256k1#readme
diff --git a/src/Crypto/Secp256k1.hs b/src/Crypto/Secp256k1.hs
--- a/src/Crypto/Secp256k1.hs
+++ b/src/Crypto/Secp256k1.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
 {-|
 Module      : Crypto.Secp256k1
 Description : Public SECP256K1 cryptographic functions