diff --git a/Network/HTTP/ReverseProxy.hs b/Network/HTTP/ReverseProxy.hs
--- a/Network/HTTP/ReverseProxy.hs
+++ b/Network/HTTP/ReverseProxy.hs
@@ -23,7 +23,7 @@
 import qualified Network.Wai as WAI
 import qualified Network.HTTP.Conduit as HC
 import Control.Exception.Lifted (try, finally)
-import Blaze.ByteString.Builder (fromByteString)
+import Blaze.ByteString.Builder (fromByteString, flush)
 import Data.Word8 (isSpace, _colon, toLower, _cr)
 import qualified Data.ByteString.Char8 as S8
 import qualified Network.HTTP.Types as HT
@@ -155,7 +155,8 @@
 #endif
                     , HC.responseTimeout = wpsTimeout wps
                     }
-                bodySrc = mapOutput fromByteString $ WAI.requestBody req
+                fbs bs = fromByteString bs <> flush
+                bodySrc = mapOutput fbs $ WAI.requestBody req
                 bodyChunked = HC.RequestBodySourceChunked bodySrc
 #if MIN_VERSION_wai(1, 4, 0)
                 body =
diff --git a/http-reverse-proxy.cabal b/http-reverse-proxy.cabal
--- a/http-reverse-proxy.cabal
+++ b/http-reverse-proxy.cabal
@@ -1,5 +1,5 @@
 name:                http-reverse-proxy
-version:             0.1.1.5
+version:             0.1.1.6
 synopsis:            Reverse proxy HTTP requests, either over raw sockets or with WAI
 description:         Provides a simple means of reverse-proxying HTTP requests. The raw approach uses the same technique as leveraged by keter, whereas the WAI approach performs full request/response parsing via WAI and http-conduit.
 homepage:            https://github.com/fpco/http-reverse-proxy