diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,9 @@
+## 3.2.16
+
+* In `testWithApplication`, don't `throwTo` ignorable exceptions
+  [#671](https://github.com/yesodweb/wai/issues/671), and
+  reuse `bindRandomPortTCP`
+
 ## 3.2.15
 
 * Address space leak from exception handlers
diff --git a/Network/Wai/Handler/Warp/WithApplication.hs b/Network/Wai/Handler/Warp/WithApplication.hs
--- a/Network/Wai/Handler/Warp/WithApplication.hs
+++ b/Network/Wai/Handler/Warp/WithApplication.hs
@@ -1,4 +1,4 @@
-
+{-# LANGUAGE OverloadedStrings #-}
 module Network.Wai.Handler.Warp.WithApplication (
   withApplication,
   withApplicationSettings,
@@ -11,6 +11,8 @@
 import           Control.Concurrent
 import           Control.Concurrent.Async
 import           Control.Exception
+import           Control.Monad (when)
+import           Data.Streaming.Network (bindRandomPortTCP)
 import           Network.Socket
 import           Network.Wai
 import           Network.Wai.Handler.Warp.Run
@@ -71,7 +73,9 @@
   app <- mkApp
   let wrappedApp request respond =
         app request respond `catch` \ e -> do
-          throwTo callingThread (e :: SomeException)
+          when
+            (defaultShouldDisplayException e)
+            (throwTo callingThread e)
           throwIO e
   withApplication (return wrappedApp) action
 
@@ -93,17 +97,7 @@
 --
 -- @since 3.2.4
 openFreePort :: IO (Port, Socket)
-openFreePort = do
-  let hints = defaultHints {
-          addrFlags = [AI_PASSIVE]
-        , addrSocketType = Stream
-        }
-  addr:_ <- getAddrInfo (Just hints) (Just "127.0.0.1") Nothing
-  s <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
-  bind s $ addrAddress addr
-  listen s 1
-  port <- socketPort s
-  return (fromIntegral port, s)
+openFreePort = bindRandomPortTCP "127.0.0.1"
 
 -- | Like 'openFreePort' but closes the socket before exiting.
 withFreePort :: ((Port, Socket) -> IO a) -> IO a
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.2.15
+Version:             3.2.16
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE