diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 3.0.20.1
+
+* Set `requestBodyLength` for `srequest` [#654](https://github.com/yesodweb/wai/pull/654)
+
 ## 3.0.20.0
 
 * runSessionWith (runSession variant that gives access to ClientState) [#629](https://github.com/yesodweb/wai/pull/629)
diff --git a/Network/Wai/EventSource.hs b/Network/Wai/EventSource.hs
--- a/Network/Wai/EventSource.hs
+++ b/Network/Wai/EventSource.hs
@@ -1,5 +1,10 @@
 {-|
     A WAI adapter to the HTML5 Server-Sent Events API.
+
+    If running through a proxy like Nginx you might need to add the
+    headers:
+
+    > [ ("X-Accel-Buffering", "no"), ("Cache-Control", "no-cache")]
 -}
 module Network.Wai.EventSource (
     ServerEvent(..),
diff --git a/Network/Wai/Test.hs b/Network/Wai/Test.hs
--- a/Network/Wai/Test.hs
+++ b/Network/Wai/Test.hs
@@ -176,6 +176,7 @@
                 case bss of
                     [] -> ([], S.empty)
                     x:y -> (y, x)
+            , requestBodyLength = KnownLength $ fromIntegral $ L.length bod
             }
     req'' <- addCookiesToRequest req'
     response <- liftIO $ do
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,3 +1,16 @@
-## wai-extra
+# wai-extra
 
 The goal here is to provide common features without many dependencies.
+
+
+## Example using Server-Sent Events ##
+
+There is a small example using Server-Sent Events (SSE) in the
+`./example` directory.
+
+Run the commands below to start the server on http://localhost:8080
+
+```
+$ stack build .
+$ stack exec example
+```
diff --git a/example/Main.hs b/example/Main.hs
new file mode 100644
--- /dev/null
+++ b/example/Main.hs
@@ -0,0 +1,51 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Main where
+
+import Blaze.ByteString.Builder.Char.Utf8 (fromString)
+import Control.Concurrent (forkIO, threadDelay)
+import Control.Concurrent.Chan
+import Control.Monad
+import Data.Time.Clock.POSIX (getPOSIXTime)
+import Network.HTTP.Types (status200)
+import Network.Wai (Application, Middleware, pathInfo, responseFile)
+import Network.Wai.EventSource (ServerEvent(..), eventSourceAppChan, eventSourceAppIO)
+import Network.Wai.Handler.Warp (run)
+import Network.Wai.Middleware.AddHeaders (addHeaders)
+import Network.Wai.Middleware.Gzip (gzip, def)
+
+
+app :: Chan ServerEvent -> Application
+app chan req respond =
+    case pathInfo req of
+        []     -> respond $ responseFile status200 [("Content-Type", "text/html")] "example/index.html" Nothing
+        ["esold"]  -> eventSourceAppChan chan req respond
+        ["eschan"] -> eventSourceAppChan chan req respond
+        ["esio"]   -> eventSourceAppIO eventIO req respond
+        _ -> error "unexpected pathInfo"
+
+eventChan :: Chan ServerEvent -> IO ()
+eventChan chan = forever $ do
+    threadDelay 1000000
+    time <- getPOSIXTime
+    writeChan chan (ServerEvent Nothing Nothing [fromString . show $ time])
+
+eventIO :: IO ServerEvent
+eventIO = do
+    threadDelay 1000000
+    time <- getPOSIXTime
+    return $ ServerEvent (Just $ fromString "io")
+                         Nothing
+                         [fromString . show $ time]
+
+main :: IO ()
+main = do
+    chan <- newChan
+    _ <- forkIO . eventChan $ chan
+    run 8080 (gzip def $ headers $ app chan)
+    where
+      -- headers required for SSE to work through nginx
+      -- not required if using warp directly
+      headers :: Middleware
+      headers = addHeaders [ ("X-Accel-Buffering", "no")
+                           , ("Cache-Control", "no-cache")
+                           ]
diff --git a/wai-extra.cabal b/wai-extra.cabal
--- a/wai-extra.cabal
+++ b/wai-extra.cabal
@@ -1,5 +1,5 @@
 Name:                wai-extra
-Version:             3.0.20.0
+Version:             3.0.20.1
 Synopsis:            Provides some basic WAI handlers and middleware.
 description:
   Provides basic WAI handler and middleware functionality:
@@ -81,6 +81,11 @@
   ChangeLog.md
   README.md
 
+flag build-example
+  description:        Build example executable.
+  manual:             True
+  default:            False
+
 Library
   Build-Depends:     base                      >= 4.6 && < 5
                    , bytestring                >= 0.9.1.4
@@ -154,6 +159,22 @@
   other-modules:     Network.Wai.Middleware.RequestLogger.Internal
   default-language:          Haskell2010
   ghc-options:       -Wall
+
+executable example
+  hs-source-dirs:      example
+  main-is:             Main.hs
+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall
+  if flag(build-example)
+    build-depends:     base
+                     , wai-extra
+                     , warp
+                     , wai
+                     , time
+                     , http-types
+                     , blaze-builder
+  else
+    buildable: False
+  default-language:    Haskell2010
 
 test-suite spec
     type:            exitcode-stdio-1.0