diff --git a/Network/Wai/Application/Classic/CGI.hs b/Network/Wai/Application/Classic/CGI.hs
--- a/Network/Wai/Application/Classic/CGI.hs
+++ b/Network/Wai/Application/Classic/CGI.hs
@@ -66,7 +66,11 @@
 type TRYPATH = Either E.IOException String
 
 toCGI :: Handle -> Request -> IO ()
+#if MIN_VERSION_conduit(1,3,0)
+toCGI whdl req = runConduit (sourceRequestBody req .| CB.sinkHandle whdl)
+#else
 toCGI whdl req = sourceRequestBody req $$ CB.sinkHandle whdl
+#endif
 
 fromCGI :: Handle -> IO Response
 fromCGI rhdl = do
diff --git a/Network/Wai/Application/Classic/Conduit.hs b/Network/Wai/Application/Classic/Conduit.hs
--- a/Network/Wai/Application/Classic/Conduit.hs
+++ b/Network/Wai/Application/Classic/Conduit.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings, CPP #-}
 
 module Network.Wai.Application.Classic.Conduit (
     byteStringToBuilder
@@ -25,11 +25,19 @@
 
 ----------------------------------------------------------------
 
+#if MIN_VERSION_conduit(1,3,0)
+toResponseSource :: SealedConduitT () ByteString IO ()
+                 -> IO (ConduitT () (Flush Builder) IO ())
+toResponseSource rsrc = do
+    let src = unsealConduitT rsrc
+    return $ src .| CL.map (Chunk . byteStringToBuilder)
+#else
 toResponseSource :: ResumableSource IO ByteString
                  -> IO (Source IO (Flush Builder))
 toResponseSource rsrc = do
     (src,_) <- unwrapResumable rsrc
     return $ src $= CL.map (Chunk . byteStringToBuilder)
+#endif
 
 ----------------------------------------------------------------
 
diff --git a/Network/Wai/Application/Classic/EventSource.hs b/Network/Wai/Application/Classic/EventSource.hs
--- a/Network/Wai/Application/Classic/EventSource.hs
+++ b/Network/Wai/Application/Classic/EventSource.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings, CPP #-}
 
 module Network.Wai.Application.Classic.EventSource (
     bodyToEventSource
@@ -46,7 +46,11 @@
                                     in xs:go ys 0
             | otherwise = [bs]
 
+#if MIN_VERSION_conduit(1,3,0)
+eventSourceConduit :: ConduitT ByteString (Flush Builder) IO ()
+#else
 eventSourceConduit :: Conduit ByteString IO (Flush Builder)
+#endif
 eventSourceConduit = CL.concatMapAccum f ""
   where
     f input rest = (last xs, concatMap addFlush $ init xs)
@@ -55,5 +59,10 @@
         xs = splitDoubleLineBreak (rest `BS.append` input)
 
 -- insert Flush if exists a double line-break
+#if MIN_VERSION_conduit(1,3,0)
+bodyToEventSource :: H.BodyReader -> ConduitT () (Flush Builder) IO ()
+bodyToEventSource br = HC.bodyReaderSource br .| eventSourceConduit
+#else
 bodyToEventSource :: H.BodyReader -> Source IO (Flush Builder)
 bodyToEventSource br = HC.bodyReaderSource br $= eventSourceConduit
+#endif
diff --git a/Network/Wai/Application/Classic/RevProxy.hs b/Network/Wai/Application/Classic/RevProxy.hs
--- a/Network/Wai/Application/Classic/RevProxy.hs
+++ b/Network/Wai/Application/Classic/RevProxy.hs
@@ -87,11 +87,19 @@
 
 ----------------------------------------------------------------
 
+#if MIN_VERSION_conduit(1,3,0)
+toSource :: Maybe ByteString -> H.BodyReader -> ConduitT () (Flush Builder) IO ()
+#else
 toSource :: Maybe ByteString -> H.BodyReader -> Source IO (Flush Builder)
+#endif
 toSource (Just "text/event-stream") = bodyToEventSource
 toSource _                          = bodyToSource
 
+#if MIN_VERSION_conduit(1,3,0)
+bodyToSource :: H.BodyReader -> ConduitT () (Flush Builder) IO ()
+#else
 bodyToSource :: H.BodyReader -> Source IO (Flush Builder)
+#endif
 bodyToSource br = loop
   where
     loop = do
diff --git a/wai-app-file-cgi.cabal b/wai-app-file-cgi.cabal
--- a/wai-app-file-cgi.cabal
+++ b/wai-app-file-cgi.cabal
@@ -1,5 +1,5 @@
 Name:                   wai-app-file-cgi
-Version:                3.1.3
+Version:                3.1.4
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3