diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,8 @@
+## 3.2.2
+
+* Throwing errno for pread [#499](https://github.com/yesodweb/wai/issues/499).
+* Makeing compilable on Windows [#505](https://github.com/yesodweb/wai/issues/505).
+
 ## 3.2.1
 
 * Add back `warpVersion`
@@ -10,7 +15,7 @@
 * The performance of HTTP/2 was drastically improved. Now the performance of HTTP/2 is almost the same as that of HTTP/1.1.
 * The logic to handle files in HTTP/2 is now identical to that in HTTP/1.1.
 * Internal stuff was removed from the Network.Wai.Handler.Warp module according to [the plan](http://www.yesodweb.com/blog/2015/06/cleaning-up-warp-apis).
-	
+
 ## 3.1.12
 
 * Setting lower bound for auto-update [#495](https://github.com/yesodweb/wai/issues/495)
diff --git a/Network/Wai/Handler/Warp/HTTP2/Sender.hs b/Network/Wai/Handler/Warp/HTTP2/Sender.hs
--- a/Network/Wai/Handler/Warp/HTTP2/Sender.hs
+++ b/Network/Wai/Handler/Warp/HTTP2/Sender.hs
@@ -296,7 +296,7 @@
     (start, bytes) <- fileStartEnd path mpart
     -- fixme: how to close Handle? GC does it at this moment.
     hdl <- IO.openBinaryFile path IO.ReadMode
-    IO.hSeek h IO.AbsoluteSeek start
+    IO.hSeek hdl IO.AbsoluteSeek start
     len <- IO.hGetBufSome hdl datBuf (mini room bytes)
     let bytes' = bytes - fromIntegral len
     -- fixme: connWriteBuffer connBufferSize
diff --git a/Network/Wai/Handler/Warp/SendFile.hs b/Network/Wai/Handler/Warp/SendFile.hs
--- a/Network/Wai/Handler/Warp/SendFile.hs
+++ b/Network/Wai/Handler/Warp/SendFile.hs
@@ -9,7 +9,7 @@
 #endif
   ) where
 
-import Control.Monad (void)
+import Control.Monad (void, when)
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as BS
 import Network.Socket (Socket)
@@ -17,7 +17,6 @@
 import Network.Wai.Handler.Warp.Types
 
 #ifdef WINDOWS
-import Control.Monad (when)
 import Data.ByteString.Internal (ByteString(..))
 import Foreign.ForeignPtr (newForeignPtr_)
 import Foreign.Ptr (plusPtr)
@@ -27,6 +26,7 @@
 import Control.Applicative ((<$>))
 # endif
 import Control.Exception
+import Foreign.C.Error (throwErrno)
 import Foreign.C.Types
 import Foreign.Ptr (Ptr, castPtr, plusPtr)
 import Network.Sendfile
@@ -143,8 +143,10 @@
           loop fd (len - n') (off + n')
 
 positionRead :: Fd -> Buffer -> BufSize -> Integer -> IO Int
-positionRead fd buf siz off =
-    fromIntegral <$> c_pread fd (castPtr buf) (fromIntegral siz) (fromIntegral off)
+positionRead fd buf siz off = do
+    bytes <- fromIntegral <$> c_pread fd (castPtr buf) (fromIntegral siz) (fromIntegral off)
+    when (bytes < 0) $ throwErrno "positionRead"
+    return bytes
 
 foreign import ccall unsafe "pread"
   c_pread :: Fd -> Ptr CChar -> ByteCount -> FileOffset -> IO CSsize
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.2.1
+Version:             3.2.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE