diff --git a/Network/Wai/Handler/Warp/Header.hs b/Network/Wai/Handler/Warp/Header.hs
--- a/Network/Wai/Handler/Warp/Header.hs
+++ b/Network/Wai/Handler/Warp/Header.hs
@@ -49,17 +49,19 @@
 indexResponseHeader :: ResponseHeaders -> IndexedHeader
 indexResponseHeader hdr = traverseHeader hdr responseMaxIndex responseKeyIndex
 
-idxServer :: Int
+idxServer, idxDate :: Int
 --idxContentLength = 0
 idxServer        = 1
+idxDate          = 2
 
 -- | The size for 'IndexedHeader' for HTTP Response.
 responseMaxIndex :: Int
-responseMaxIndex = 1
+responseMaxIndex = 2
 
 responseKeyIndex :: HeaderName -> Int
 responseKeyIndex "content-length" = idxContentLength
 responseKeyIndex "server"         = idxServer
+responseKeyIndex "date"           = idxDate
 responseKeyIndex _                = -1
 
 ----------------------------------------------------------------
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
@@ -173,7 +173,7 @@
     rspidxhdr = indexResponseHeader hs0
     th = threadHandle ii
     dc = dateCacher ii
-    addServerAndDate = addDate dc . addServer rspidxhdr
+    addServerAndDate = addDate dc rspidxhdr . addServer rspidxhdr
     mRange = reqidxhdr ! idxRange
     reqinfo@(isPersist,_) = infoFromRequest req reqidxhdr
     (isKeepAlive, needsChunked) = infoFromResponse rspidxhdr reqinfo
@@ -378,10 +378,12 @@
       ( '/'
       : showInt total ""))
 
-addDate :: D.DateCache -> H.ResponseHeaders -> IO H.ResponseHeaders
-addDate dc hdrs = do
-    gmtdate <- D.getDate dc
-    return $ (H.hDate, gmtdate) : hdrs
+addDate :: D.DateCache -> IndexedHeader -> H.ResponseHeaders -> IO H.ResponseHeaders
+addDate dc rspidxhdr hdrs = case rspidxhdr ! idxDate of
+    Nothing -> do
+        gmtdate <- D.getDate dc
+        return $ (H.hDate, gmtdate) : hdrs
+    Just _ -> return hdrs
 
 ----------------------------------------------------------------
 
diff --git a/test/RunSpec.hs b/test/RunSpec.hs
--- a/test/RunSpec.hs
+++ b/test/RunSpec.hs
@@ -25,6 +25,7 @@
 import Control.Exception.Lifted (bracket, try, IOException, onException)
 import Data.Conduit.Network (bindPort)
 import Network.Socket (sClose)
+import qualified Network.HTTP as HTTP
 
 main :: IO ()
 main = hspec spec
@@ -309,3 +310,15 @@
                 hPutStr handle "67890"
                 hFlush handle
                 timeout 100000 (S.hGet handle 10) >>= (`shouldBe` Just "6677889900")
+
+    it "only one date and server header" $ do
+        let app _ = return $ responseLBS status200
+                [ ("server", "server")
+                , ("date", "date")
+                ] ""
+        withApp defaultSettings app $ \port -> do
+            Right res <- HTTP.simpleHTTP (HTTP.getRequest $ "http://127.0.0.1:" ++ show port)
+            map HTTP.hdrValue (HTTP.retrieveHeaders HTTP.HdrServer res)
+                `shouldBe` ["server"]
+            map HTTP.hdrValue (HTTP.retrieveHeaders HTTP.HdrDate res)
+                `shouldBe` ["date"]
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             2.1.1
+Version:             2.1.1.1
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE