diff --git a/Setup.hs b/Setup.hs
deleted file mode 100644
--- a/Setup.hs
+++ /dev/null
@@ -1,2 +0,0 @@
-import Distribution.Simple
-main = defaultMain
diff --git a/network-messagepack-rpc.cabal b/network-messagepack-rpc.cabal
--- a/network-messagepack-rpc.cabal
+++ b/network-messagepack-rpc.cabal
@@ -1,5 +1,5 @@
 name:                network-messagepack-rpc
-version:             0.1.1.0
+version:             0.1.1.1
 synopsis:            MessagePack RPC
 description:         [MessagePack RPC](https://github.com/msgpack-rpc/msgpack-rpc/blob/master/spec.md) library based on the "data-msgpack" package.
 homepage:            https://github.com/iij-ii/direct-hs/tree/master/network-messagepack-rpc
diff --git a/src/Network/MessagePack/RPC/Client.hs b/src/Network/MessagePack/RPC/Client.hs
--- a/src/Network/MessagePack/RPC/Client.hs
+++ b/src/Network/MessagePack/RPC/Client.hs
@@ -37,6 +37,7 @@
 import qualified Data.IORef              as IORef
 import qualified Data.MessagePack        as MsgPack
 import           Data.Monoid             ((<>))
+import           System.IO               (hPrint, stderr)
 import           System.Timeout          (timeout)
 
 import           Data.MessagePack.RPC
@@ -95,12 +96,13 @@
     { notificationHandler = \_ _ _ -> return ()
     , requestHandler      = \_ _ _ _ -> return ()
     , logger              = \_ -> return ()
-    , exceptionHandlers   = [E.Handler $ \(E.SomeException _) -> return ()]
+    , exceptionHandlers   = [E.Handler $ \(E.SomeException e) -> hPrint stderr e]
     , formatter           = show
     , waitRequestHandler  = False
     }
 
 -- | Backend IO functions.
+--   Any receiving / sending actions are performed by calling these functions.
 data Backend = Backend {
     backendSend  :: B.ByteString -> IO () -- ^ Sending
   , backendRecv  :: IO B.ByteString -- ^ Receiving