1 files changed, 6 insertions, 0 deletions

diff --git a/src/Data/BEncode/Types.hs b/src/Data/BEncode/Types.hs
index 15f570f..c1e1f01 100644
--- a/src/Data/BEncode/Types.hs
+++ b/src/Data/BEncode/Types.hs
@@ -7,6 +7,7 @@
 --
 --   Types for working with bencode data.
 --
+{-# LANGUAGE CPP #-}
 module Data.BEncode.Types
        ( -- * Types
          BInteger
@@ -51,6 +52,11 @@ data BValue
   | BDict     BDict    -- ^ bencode key-value dictionary.
     deriving (Show, Read, Eq, Ord)
 
+#if !MIN_VERSION_bytestring(0,10,0)
+instance NFData ByteString where
+    rnf s = seq s ()
+#endif
+
 instance NFData BValue where
     rnf (BInteger i) = rnf i
     rnf (BString  s) = rnf s