diff --git a/Network/Wai/Handler/Warp.hs b/Network/Wai/Handler/Warp.hs
--- a/Network/Wai/Handler/Warp.hs
+++ b/Network/Wai/Handler/Warp.hs
@@ -29,6 +29,7 @@
   , settingsPort
   , settingsHost
   , settingsOnException
+  , settingsOnExceptionResponse
   , settingsOnOpen
   , settingsOnClose
   , settingsTimeout
@@ -37,6 +38,8 @@
   , settingsFdCacheDuration
   , settingsBeforeMainLoop
   , settingsNoParsePath
+    -- ** Debugging
+  , exceptionResponseForDebug
     -- * Data types
   , HostPreference (..)
   , Port
diff --git a/Network/Wai/Handler/Warp/Request.hs b/Network/Wai/Handler/Warp/Request.hs
--- a/Network/Wai/Handler/Warp/Request.hs
+++ b/Network/Wai/Handler/Warp/Request.hs
@@ -87,7 +87,7 @@
 
 headerLines :: Sink ByteString IO [ByteString]
 headerLines =
-    await >>= maybe (throwIO ConnectionClosedByPeer) (push (THStatus 0 id id))
+    await >>= maybe (throwIO (NotEnoughLines [])) (push (THStatus 0 id id))
 
 ----------------------------------------------------------------
 
diff --git a/Network/Wai/Handler/Warp/Run.hs b/Network/Wai/Handler/Warp/Run.hs
--- a/Network/Wai/Handler/Warp/Run.hs
+++ b/Network/Wai/Handler/Warp/Run.hs
@@ -16,7 +16,6 @@
 import qualified Data.Conduit.List as CL
 import Data.Conduit.Network (bindPort)
 import Network (sClose, Socket)
-import qualified Network.HTTP.Types as H
 import Network.Socket (accept, SockAddr)
 import qualified Network.Socket.ByteString as Sock
 import Network.Wai
@@ -198,7 +197,10 @@
         -- Wait a second hoping that resource will be available.
         threadDelay 1000000
         getConnLoop
-    onE = settingsOnException set
+    onE mreq e =
+        case fromException e of
+            Just (NotEnoughLines []) -> return ()
+            _ -> settingsOnException set mreq e
     onOpen = settingsOnOpen set
     onClose = settingsOnClose set
 
@@ -218,18 +220,21 @@
                 -> IO ()
 serveConnection conn ii addr settings app = do
     istatus <- newIORef False
-    recvSendLoop istatus (connSource conn th istatus) `onException` send500 istatus
+    recvSendLoop istatus (connSource conn th istatus) `E.catch` \e -> do
+        sendErrorResponse istatus e
+        throwIO (e :: SomeException)
+
   where
     th = threadHandle ii
 
-    send500 istatus = do
+    sendErrorResponse istatus e = do
         status <- readIORef istatus
         when status $ void $ mask $ \restore ->
-            sendResponse conn ii restore dummyreq defaultIndexRequestHeader internalError
+            sendResponse conn ii restore dummyreq defaultIndexRequestHeader (errorResponse e)
 
     dummyreq = defaultRequest { remoteHost = addr }
 
-    internalError = responseLBS H.internalServerError500 [(H.hContentType, "text/plain")] "Something went wrong"
+    errorResponse e = settingsOnExceptionResponse settings e
 
     recvSendLoop istatus fromClient = do
         (req, idxhdr, getSource) <- recvRequest settings conn ii addr fromClient
diff --git a/Network/Wai/Handler/Warp/Settings.hs b/Network/Wai/Handler/Warp/Settings.hs
--- a/Network/Wai/Handler/Warp/Settings.hs
+++ b/Network/Wai/Handler/Warp/Settings.hs
@@ -1,10 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
+
 module Network.Wai.Handler.Warp.Settings where
 
 import Control.Exception
 import qualified Data.ByteString as S
+import qualified Data.ByteString.Lazy.Char8 as L8
 import Data.Conduit
 import Data.Conduit.Network (HostPreference (HostIPv4))
 import GHC.IO.Exception (IOErrorType(..))
+import qualified Network.HTTP.Types as H
 import Network.Wai
 import Network.Wai.Handler.Warp.Timeout
 import Network.Wai.Handler.Warp.Types
@@ -21,6 +25,12 @@
     { settingsPort :: Int -- ^ Port to listen on. Default value: 3000
     , settingsHost :: HostPreference -- ^ Default value: HostIPv4
     , settingsOnException :: Maybe Request -> SomeException -> IO () -- ^ What to do with exceptions thrown by either the application or server. Default: ignore server-generated exceptions (see 'InvalidRequest') and print application-generated applications to stderr.
+    , settingsOnExceptionResponse :: SomeException -> Response
+      -- ^ A function to create `Response` when an exception occurs.
+      --
+      -- Default: 500, text/plain, \"Something went wrong\"
+      --
+      -- Since 2.0.3
     , settingsOnOpen :: IO () -- ^ What to do when a connection is open. Default: do nothing.
     , settingsOnClose :: IO ()  -- ^ What to do when a connection is close. Default: do nothing.
     , settingsTimeout :: Int -- ^ Timeout value in seconds. Default value: 30
@@ -52,6 +62,7 @@
     { settingsPort = 3000
     , settingsHost = HostIPv4
     , settingsOnException = defaultExceptionHandler
+    , settingsOnExceptionResponse = defaultExceptionResponse
     , settingsOnOpen = return ()
     , settingsOnClose = return ()
     , settingsTimeout = 30
@@ -83,3 +94,10 @@
 
     sh :: SomeException -> IO ()
     sh x = hPrint stderr x
+
+defaultExceptionResponse :: SomeException -> Response
+defaultExceptionResponse _ = responseLBS H.internalServerError500 [(H.hContentType, "text/plain")] "Something went wrong"
+
+-- | Default implementation of 'settingsOnExceptionResponse' for the debugging purpose. 500, text/plain, a showed exception.
+exceptionResponseForDebug :: SomeException -> Response
+exceptionResponseForDebug e = responseLBS H.internalServerError500 [(H.hContentType, "text/plain")] (L8.pack $ "Exception: " ++ show e)
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             2.0.3.1
+Version:             2.0.3.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE