1 files changed, 5 insertions, 0 deletions

diff --git a/src/Network/BitTorrent/Exchange/Block.hs b/src/Network/BitTorrent/Exchange/Block.hs
index d06fe727..8e3ef91f 100644
--- a/src/Network/BitTorrent/Exchange/Block.hs
+++ b/src/Network/BitTorrent/Exchange/Block.hs
@@ -35,6 +35,7 @@ import Control.Applicative
 import Data.Aeson.TH
 import Data.ByteString.Lazy as BL
 import Data.Char
+import Data.Default
 import Data.List as L
 import Data.Serialize as S
 import Data.Typeable
@@ -87,6 +88,10 @@ data BlockIx = BlockIx {
 
 $(deriveJSON omitRecordPrefix ''BlockIx)
 
+-- | First block in torrent. Useful for debugging.
+instance Default BlockIx where
+  def = BlockIx 0 0 defaultTransferSize
+
 getInt :: S.Get Int
 getInt = fromIntegral <$> S.getWord32be
 {-# INLINE getInt #-}