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
@@ -111,8 +111,6 @@
 import qualified Data.CaseInsensitive as CI
 import System.IO (hPutStrLn, stderr)
 
-import Data.List (delete)
-
 #if WINDOWS
 import Control.Concurrent (threadDelay)
 import qualified Control.Concurrent.MVar as MV
@@ -616,9 +614,8 @@
 serverHeader :: H.RequestHeaders -> H.RequestHeaders
 serverHeader hdrs = case lookup key hdrs of
     Nothing  -> server : hdrs
-    Just svr -> servers svr : delete (key,svr) hdrs
+    Just _ -> hdrs
  where
     key = "Server"
     ver = B.pack $ "Warp/" ++ warpVersion
     server = (key, ver)
-    servers svr = (key, S.concat [svr, " ", ver])
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             0.4.6.1
+Version:             0.4.6.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             BSD3
 License-file:        LICENSE