diff --git a/Yesod/Content.hs b/Yesod/Content.hs
index e8fe59b0..10a83557 100644
--- a/Yesod/Content.hs
+++ b/Yesod/Content.hs
@@ -45,7 +45,6 @@ module Yesod.Content
       -- * Utilities
     , formatW3
     , formatRFC1123
-    , formatCookieExpires
 #if TEST
     , testSuite
 #endif
@@ -260,7 +259,3 @@ formatW3 = formatTime defaultTimeLocale "%FT%X-00:00"
 -- | Format as per RFC 1123.
 formatRFC1123 :: UTCTime -> String
 formatRFC1123 = formatTime defaultTimeLocale "%a, %d %b %Y %X %Z"
-
--- | Format a 'UTCTime' for a cookie.
-formatCookieExpires :: UTCTime -> String
-formatCookieExpires = formatTime defaultTimeLocale "%a, %d-%b-%Y %X GMT"
diff --git a/Yesod/Dispatch.hs b/Yesod/Dispatch.hs
index 27847cfc..174c707b 100644
--- a/Yesod/Dispatch.hs
+++ b/Yesod/Dispatch.hs
@@ -52,6 +52,9 @@ import qualified Network.Wai.Handler.CGI as CGI
 import System.Environment (getEnvironment)
 
 import qualified Data.ByteString.Char8 as B
+import qualified Data.ByteString as S
+import qualified Data.ByteString.Lazy as L
+import Blaze.ByteString.Builder (toLazyByteString)
 
 import Control.Concurrent.MVar
 import Control.Arrow ((***))
@@ -63,6 +66,7 @@ import Data.Maybe
 import Web.ClientSession
 import qualified Web.ClientSession as CS
 import Data.Char (isUpper)
+import Web.Cookie (parseCookies, SetCookie (..), renderSetCookie)
 
 import Data.Serialize
 import qualified Data.Serialize as Ser
@@ -447,10 +451,15 @@ headerToPair :: (Int -> UTCTime) -- ^ minutes -> expiration time
              -> Header
              -> (W.ResponseHeader, B.ByteString)
 headerToPair getExpires (AddCookie minutes key value) =
-    let expires = getExpires minutes
-     in ("Set-Cookie", charsToBs
-                            $ key ++ "=" ++ value ++"; path=/; expires="
-                              ++ formatCookieExpires expires)
+    ("Set-Cookie", builderToBS $ renderSetCookie $ SetCookie
+        { setCookieName = B.pack key -- FIXME check for non-ASCII
+        , setCookieValue = B.pack value -- FIXME check for non-ASCII
+        , setCookiePath = Just "/" -- FIXME make a config option, or use approot?
+        , setCookieExpires = Just $ getExpires minutes
+        , setCookieDomain = Nothing
+        })
+  where
+    builderToBS = S.concat . L.toChunks . toLazyByteString
 headerToPair _ (DeleteCookie key) =
     ("Set-Cookie", charsToBs $
      key ++ "=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT")
diff --git a/yesod.cabal b/yesod.cabal
index fdff1e9b..136a3083 100644
--- a/yesod.cabal
+++ b/yesod.cabal
@@ -56,6 +56,7 @@ library
                    , containers                >= 0.2      && < 0.5
                    , monad-peel                >= 0.1      && < 0.2
                    , enumerator                >= 0.4      && < 0.5
+                   , cookie                    >= 0.0      && < 0.1
     exposed-modules: Yesod
                      Yesod.Content
                      Yesod.Dispatch