diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 3.2.9
+
+* Fixing a space leak. [#586] https://github.com/yesodweb/wai/pull/586
+
 ## 3.2.8
 
 * Fixing HTTP2 requestBodyLength. [#573](https://github.com/yesodweb/wai/pull/573)
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
@@ -364,7 +364,7 @@
 setProxyProtocolOptional :: Settings -> Settings
 setProxyProtocolOptional y = y { settingsProxyProtocol = ProxyProtocolOptional }
 
--- | Size in bytes read to prevent Slowloris protection. Default value: 2048
+-- | Size in bytes read to prevent Slowloris attacks. Default value: 2048
 --
 -- Since 3.1.2
 setSlowlorisSize :: Int -> Settings -> Settings
diff --git a/Network/Wai/Handler/Warp/Response.hs b/Network/Wai/Handler/Warp/Response.hs
--- a/Network/Wai/Handler/Warp/Response.hs
+++ b/Network/Wai/Handler/Warp/Response.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE BangPatterns #-}
 
 module Network.Wai.Handler.Warp.Response (
     sendResponse
@@ -176,7 +177,8 @@
           | isHead                  -> RspNoBody
           | otherwise               -> RspStream fb needsChunked th
         ResponseRaw raw _           -> RspRaw raw src (T.tickle th)
-    ret = case response of
+    -- Make sure we don't hang on to 'response' (avoid space leak)
+    !ret = case response of
         ResponseFile    {} -> isPersist
         ResponseBuilder {} -> isKeepAlive
         ResponseStream  {} -> isKeepAlive
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.2.8
+Version:             3.2.9
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE