diff --git a/Network/Wai/Application/Classic/EventSource.hs b/Network/Wai/Application/Classic/EventSource.hs
new file mode 100644
--- /dev/null
+++ b/Network/Wai/Application/Classic/EventSource.hs
@@ -0,0 +1,58 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Network.Wai.Application.Classic.EventSource (
+  toResponseEventSource
+) where
+
+import Blaze.ByteString.Builder
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as BS
+import Data.Conduit
+import qualified Data.Conduit.List as CL
+
+lineBreak :: ByteString -> Int -> Maybe Int
+lineBreak bs n = go
+  where
+    len = BS.length bs
+    go | n >= len = Nothing
+       | otherwise = case bs `BS.index` n of
+                         13 -> go' (n+1)
+                         10 -> Just (n+1)
+                         _ -> Nothing
+    go' n' | n' >= len = Just n'
+           | otherwise = case bs `BS.index` n' of
+                             10 -> Just (n'+1)
+                             _ -> Just n'
+
+-- splitDoubleLineBreak "aaa\n\nbbb" == ["aaa\n\n", "bbb"]
+-- splitDoubleLineBreak "aaa\n\nbbb\n\n" == ["aaa\n\n", "bbb\n\n", ""]
+-- splitDoubleLineBreak "aaa\r\n\rbbb\n\r\n" == ["aaa\r\n\r", "bbb\n\r\n", ""]
+-- splitDoubleLineBreak "aaa" == ["aaa"]
+-- splitDoubleLineBreak "" == [""]
+splitDoubleLineBreak :: ByteString -> [ByteString]
+splitDoubleLineBreak str = go str 0
+  where
+    go bs n | n < BS.length str =
+                    case lineBreak bs n of
+                        Nothing -> go bs (n+1)
+                        Just n' ->
+                            case lineBreak bs n' of
+                                Nothing -> go bs (n+1)
+                                Just n'' ->
+                                    let (xs,ys) = BS.splitAt n'' bs
+                                    in xs:go ys 0
+            | otherwise = [bs]
+
+eventSourceConduit :: Conduit ByteString (ResourceT IO) (Flush Builder)
+eventSourceConduit = CL.concatMapAccum f ""
+  where
+    f input rest = (last xs, concatMap addFlush $ init xs)
+      where
+        addFlush x = [Chunk (fromByteString x), Flush]
+        xs = splitDoubleLineBreak (rest `BS.append` input)
+
+-- insert Flush if exists a double line-break
+toResponseEventSource :: ResumableSource (ResourceT IO) ByteString
+                      -> (ResourceT IO) (Source (ResourceT IO) (Flush Builder))
+toResponseEventSource rsrc = do
+    (src,_) <- unwrapResumable rsrc
+    return $ src $= eventSourceConduit
diff --git a/Network/Wai/Application/Classic/File.hs b/Network/Wai/Application/Classic/File.hs
--- a/Network/Wai/Application/Classic/File.hs
+++ b/Network/Wai/Application/Classic/File.hs
@@ -120,7 +120,7 @@
 
 tryGetFile :: HandlerInfo -> Bool -> Lang -> Rsp
 tryGetFile (HandlerInfo spec req file _) ishtml lang = do
-    finfo <- liftIO $ (getFileInfo spec) (lang file)
+    finfo <- liftIO $ getFileInfo spec (lang file)
     let mtime = fileInfoTime finfo
         size = fileInfoSize finfo
         sfile = fileInfoName finfo
@@ -150,7 +150,7 @@
 
 tryHeadFile :: HandlerInfo -> Bool -> Lang -> Rsp
 tryHeadFile (HandlerInfo spec req file _) ishtml lang = do
-    finfo <- liftIO $ (getFileInfo spec) (lang file)
+    finfo <- liftIO $ getFileInfo spec (lang file)
     let mtime = fileInfoTime finfo
         size = fileInfoSize finfo
         date = fileInfoDate finfo
@@ -172,7 +172,7 @@
 
 tryRedirectFile :: HandlerInfo -> Lang -> Rsp
 tryRedirectFile (HandlerInfo spec req file _) lang = do
-    _ <- liftIO $ (getFileInfo spec) (lang file)
+    _ <- liftIO $ getFileInfo spec (lang file)
     return $ RspSpec movedPermanently301 (BodyFileNoBody hdr)
   where
     hdr = redirectHeader req
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
@@ -16,9 +16,11 @@
 import Network.HTTP.Types
 import Network.Wai
 import Network.Wai.Application.Classic.Conduit
+import Network.Wai.Application.Classic.EventSource
 import Network.Wai.Application.Classic.Field
 import Network.Wai.Application.Classic.Path
 import Network.Wai.Application.Classic.Types
+import Blaze.ByteString.Builder (Builder)
 import Prelude hiding (catch)
 
 toHTTPRequest :: Request -> RevProxyRoute -> Int64 -> H.Request (ResourceT IO)
@@ -75,7 +77,7 @@
     H.Response status _ hdr rdownbody <- http httpReq mgr
     let hdr' = fixHeader hdr
     liftIO $ logger cspec req status (fromIntegral <$> mlen)
-    ResponseSource status hdr' <$> toResponseSource rdownbody
+    ResponseSource status hdr' <$> toSource (lookup hContentType hdr') rdownbody
   where
     mgr = revProxyManager spec
     fixHeader = addVia cspec req . filter p
@@ -83,6 +85,12 @@
       | k == hContentEncoding = False
       | k == hContentLength   = False
       | otherwise              = True
+
+toSource :: Maybe BS.ByteString
+         -> ResumableSource (ResourceT IO) BS.ByteString
+         -> (ResourceT IO) (Source (ResourceT IO) (Flush Builder))
+toSource (Just "text/event-stream") = toResponseEventSource
+toSource _                          = toResponseSource
 
 type Resp = ResourceT IO (H.Response (ResumableSource (ResourceT IO) BS.ByteString))
 
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:                0.7.1
+Version:                0.7.2
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
@@ -17,6 +17,7 @@
   Exposed-Modules:      Network.Wai.Application.Classic
   Other-Modules:        Network.Wai.Application.Classic.CGI
                         Network.Wai.Application.Classic.Conduit
+                        Network.Wai.Application.Classic.EventSource
                         Network.Wai.Application.Classic.Field
                         Network.Wai.Application.Classic.File
                         Network.Wai.Application.Classic.FileInfo