diff --git a/Crypto/Hash.hs b/Crypto/Hash.hs
index 311a495..cd08a6a 100644
--- a/Crypto/Hash.hs
+++ b/Crypto/Hash.hs
@@ -17,6 +17,7 @@
 -- > hexSha3_512 bs = show (hash bs :: Digest SHA3_512)
 --
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE BangPatterns        #-}
 module Crypto.Hash
     (
     -- * Types