diff --git a/snap-server.cabal b/snap-server.cabal
--- a/snap-server.cabal
+++ b/snap-server.cabal
@@ -1,5 +1,5 @@
 name:           snap-server
-version:        1.0.3.1
+version:        1.0.3.2
 synopsis:       A web server for the Snap Framework
 description:
   Snap is a simple and fast web development framework and server written in
diff --git a/src/Snap/Internal/Http/Server/Session.hs b/src/Snap/Internal/Http/Server/Session.hs
--- a/src/Snap/Internal/Http/Server/Session.hs
+++ b/src/Snap/Internal/Http/Server/Session.hs
@@ -194,8 +194,7 @@
             let twiddleTimeout = unsafePerformIO $ do
                                    th <- readMVar thMVar
                                    return $! TM.modify th
-            let cleanupTimeout = do th <- readMVar thMVar
-                                    return $! TM.cancel th
+            let cleanupTimeout = readMVar thMVar >>= TM.cancel
 
             let !psd = PerSessionData connClose
                                       twiddleTimeout