diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,8 +1,15 @@
+## 3.1.5
+
+* Using	http-types v0.9.
+* Fixing build on OpenBSD. [#428](https://github.com/yesodweb/wai/pull/428) [#440](https://github.com/yesodweb/wai/pull/440)
+* Fixing build on Windows. [#438](https://github.com/yesodweb/wai/pull/438)
+
 ## 3.1.4
 
 * Using newer http2 library to prevent change table size attacks.
 * API for HTTP/2 server push and trailers. [#426](https://github.com/yesodweb/wai/pull/426)
 * Preventing response splitting attacks. [#435](https://github.com/yesodweb/wai/pull/435)
+* Concatenating multiple Cookie: headers in HTTP/2.
 
 ## 3.1.3
 
diff --git a/Network/Wai/Handler/Warp/Recv.hs b/Network/Wai/Handler/Warp/Recv.hs
--- a/Network/Wai/Handler/Warp/Recv.hs
+++ b/Network/Wai/Handler/Warp/Recv.hs
@@ -114,7 +114,7 @@
 receiveloop :: CInt -> Ptr Word8 -> CSize -> IO CInt
 receiveloop sock ptr size = do
 #ifdef mingw32_HOST_OS
-    bytes <- windowsThreadBlockHack . fromIntegral <$> readRawBufferPtr "recv" (FD sock 1) (castPtr ptr) 0 size
+    bytes <- windowsThreadBlockHack $ fromIntegral <$> readRawBufferPtr "recv" (FD sock 1) (castPtr ptr) 0 size
 #else
     bytes <- c_recv sock (castPtr ptr) size 0
 #endif
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
@@ -48,6 +48,7 @@
 import Data.Version (showVersion)
 import Data.Word8 (_cr, _lf)
 import qualified Network.HTTP.Types as H
+import qualified Network.HTTP.Types.Header as H
 import Network.Wai
 import Network.Wai.Handler.Warp.Buffer (toBuilderBuffer)
 import qualified Network.Wai.Handler.Warp.Date as D
@@ -379,7 +380,7 @@
 ----------------------------------------------------------------
 
 addTransferEncoding :: H.ResponseHeaders -> H.ResponseHeaders
-addTransferEncoding hdrs = (hTransferEncoding, "chunked") : hdrs
+addTransferEncoding hdrs = (H.hTransferEncoding, "chunked") : hdrs
 
 addDate :: D.DateCache -> IndexedHeader -> H.ResponseHeaders -> IO H.ResponseHeaders
 addDate dc rspidxhdr hdrs = case rspidxhdr ! idxDate of
@@ -399,7 +400,7 @@
 
 addServer :: HeaderValue -> IndexedHeader -> H.ResponseHeaders -> H.ResponseHeaders
 addServer defaultServerValue' rspidxhdr hdrs = case rspidxhdr ! idxServer of
-    Nothing -> (hServer, defaultServerValue') : hdrs
+    Nothing -> (H.hServer, defaultServerValue') : hdrs
     _       -> hdrs
 
 ----------------------------------------------------------------
diff --git a/Network/Wai/Handler/Warp/Types.hs b/Network/Wai/Handler/Warp/Types.hs
--- a/Network/Wai/Handler/Warp/Types.hs
+++ b/Network/Wai/Handler/Warp/Types.hs
@@ -11,7 +11,6 @@
 import Data.Typeable (Typeable)
 import Data.Word (Word16, Word8)
 import Foreign.Ptr (Ptr)
-import Network.HTTP.Types.Header
 import qualified Network.Wai.Handler.Warp.Date as D
 import qualified Network.Wai.Handler.Warp.FdCache as F
 import qualified Network.Wai.Handler.Warp.Timeout as T
@@ -29,18 +28,6 @@
 
 -- | The type for header value used with 'HeaderName'.
 type HeaderValue = ByteString
-
-hTransferEncoding :: HeaderName
-hTransferEncoding = "Transfer-Encoding"
-
-hContentRange :: HeaderName
-hContentRange = "Content-Range"
-
-hAcceptRanges :: HeaderName
-hAcceptRanges = "Accept-Ranges"
-
-hServer :: HeaderName
-hServer = "Server"
 
 ----------------------------------------------------------------
 
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.1.4
+Version:             3.1.5
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE
@@ -40,7 +40,7 @@
                    , case-insensitive          >= 0.2
                    , containers
                    , ghc-prim
-                   , http-types                >= 0.8.5
+                   , http-types                >= 0.9
                    , iproute                   >= 1.3.1
                    , http2                     >= 1.1
                    , simple-sendfile           >= 0.2.7    && < 0.3
@@ -95,7 +95,6 @@
       Cpp-Options:   -DWARP_DEBUG
   if (os(linux) || os(freebsd) || os(darwin)) && flag(allow-sendfilefd)
       Cpp-Options:   -DSENDFILEFD
-      Other-modules: Network.Wai.Handler.Warp.MultiMap
   if os(windows)
       Cpp-Options:   -DWINDOWS
       Build-Depends: time
@@ -103,6 +102,7 @@
   else
       Build-Depends: unix
                    , http-date
+      Other-modules: Network.Wai.Handler.Warp.MultiMap
 
 Test-Suite doctest
   Type:                 exitcode-stdio-1.0
@@ -139,7 +139,7 @@
                    , case-insensitive          >= 0.2
                    , ghc-prim
                    , HTTP
-                   , http-types                >= 0.8.4
+                   , http-types                >= 0.9
                    , iproute                   >= 1.3.1
                    , lifted-base               >= 0.1
                    , simple-sendfile           >= 0.2.4    && < 0.3