diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,8 @@
+## 3.1.7
+
+* A concatenated Cookie header is prepended to the headers to ensure that it flows pseudo headers. [#454](https://github.com/yesodweb/wai/pull/454)
+* Providing a new settings: `setHTTP2Disabled` [#450](https://github.com/yesodweb/wai/pull/450)
+
 ## 3.1.6
 
 * Adding back http-types 0.8 support [#449](https://github.com/yesodweb/wai/pull/449)
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
@@ -76,6 +76,7 @@
   , setProxyProtocolRequired
   , setProxyProtocolOptional
   , setSlowlorisSize
+  , setHTTP2Disabled
     -- ** Getters
   , getPort
   , getHost
@@ -355,6 +356,12 @@
 -- Since 3.1.2
 setSlowlorisSize :: Int -> Settings -> Settings
 setSlowlorisSize x y = y { settingsSlowlorisSize = x }
+
+-- | Disable HTTP2.
+--
+-- Since 3.1.7
+setHTTP2Disabled :: Settings -> Settings
+setHTTP2Disabled y = y { settingsHTTP2Enabled = False }
 
 -- | Explicitly pause the slowloris timeout.
 --
diff --git a/Network/Wai/Handler/Warp/HTTP2/HPACK.hs b/Network/Wai/Handler/Warp/HTTP2/HPACK.hs
--- a/Network/Wai/Handler/Warp/HTTP2/HPACK.hs
+++ b/Network/Wai/Handler/Warp/HTTP2/HPACK.hs
@@ -10,7 +10,6 @@
 import qualified Data.ByteString.Char8 as B8
 import Data.CaseInsensitive (foldedCase)
 import Data.IORef (readIORef, writeIORef)
-import qualified Data.List as L
 import Network.HPACK
 import qualified Network.HTTP.Types as H
 import Network.HTTP2
@@ -63,9 +62,11 @@
 -- >>> concatCookie [("foo","bar")]
 -- [("foo","bar")]
 -- >>> concatCookie [("cookie","a=b"),("foo","bar"),("cookie","c=d"),("cookie","e=f")]
--- [("cookie","a=b; c=d; e=f"),("foo","bar")]
+-- [("foo","bar"),("cookie","a=b; c=d; e=f")]
 concatCookie :: HeaderList -> HeaderList
-concatCookie hdr = case L.partition (\x -> fst x == "cookie") hdr of
-    ([],_)           -> hdr
-    (cookies,others) -> let cookieValue = B.intercalate "; " (map snd cookies)
-                        in ("cookie",cookieValue) : others
+concatCookie = collect []
+  where
+    collect cookies (("cookie",c):rest) = collect (cookies ++ [c]) rest
+    collect cookies (h:rest) = h : collect cookies rest
+    collect [] [] = []
+    collect cookies [] = [("cookie", B.intercalate "; " cookies)]
diff --git a/Network/Wai/Handler/Warp/Run.hs b/Network/Wai/Handler/Warp/Run.hs
--- a/Network/Wai/Handler/Warp/Run.hs
+++ b/Network/Wai/Handler/Warp/Run.hs
@@ -387,7 +387,7 @@
                        return (True, bs0)
                      else
                        return (False, bs0)
-    if h2 then do
+    if settingsHTTP2Enabled settings && h2 then do
         recvN <- makeReceiveN bs (connRecv conn) (connRecvBuf conn)
         -- fixme: origAddr
         http2 conn ii origAddr transport settings recvN app2
diff --git a/Network/Wai/Handler/Warp/Settings.hs b/Network/Wai/Handler/Warp/Settings.hs
--- a/Network/Wai/Handler/Warp/Settings.hs
+++ b/Network/Wai/Handler/Warp/Settings.hs
@@ -92,6 +92,10 @@
       -- ^ Size of bytes read to prevent Slowloris protection. Default value: 2048
       --
       -- Since 3.1.2.
+    , settingsHTTP2Enabled :: Bool
+      -- ^ Whether to enable HTTP2 ALPN/upgrades. Default: True
+      --
+      -- Since 3.1.7.
     }
 
 -- | Specify usage of the PROXY protocol.
@@ -123,6 +127,7 @@
     , settingsMaximumBodyFlush = Just 8192
     , settingsProxyProtocol = ProxyProtocolNone
     , settingsSlowlorisSize = 2048
+    , settingsHTTP2Enabled = True
     }
 
 -- | Apply the logic provided by 'defaultOnException' to determine if an
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.1.6
+Version:             3.1.7
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE