diff --git a/Happstack/Server/JMacro.hs b/Happstack/Server/JMacro.hs
--- a/Happstack/Server/JMacro.hs
+++ b/Happstack/Server/JMacro.hs
@@ -1,18 +1,67 @@
+{-# LANGUAGE QuasiQuotes #-}
+
 -- |This modules provides support for using JMacro with Happstack.
 --
 -- It provides the instance,
 --
--- > instance ToMessage JStat 
+-- > instance ToMessage JStat
 --
 -- Which will serve a 'JStat' value as @text/javascript; charset=UTF-8@.
-module Happstack.Server.JMacro where
+-- The rendered JavaScript will be wrapped in an anonymous function that is
+-- then called, so as to ensure the statements execute in a local scope.
+-- An implication of this is that top-level unhygienic variables in JMacro
+-- will /not/ be globally available; instead, you should set properties on
+-- the global @window@ object.
+module Happstack.Server.JMacro (jmResponse) where
 
-import qualified Data.ByteString.Char8 as S
-import Data.ByteString.Lazy.UTF8       as LB
-import Happstack.Server                (ToMessage(..))
-import Language.Javascript.JMacro      (JStat(..), renderJs)
-import Text.PrettyPrint                (Style(mode), Mode(OneLineMode), style, renderStyle)
+import qualified Data.ByteString           as B
+import qualified Data.ByteString.Char8     as S
+import qualified Data.ByteString.Lazy.UTF8 as LB
 
+import Data.ByteString.Base64.URL (encode)
+import Data.Digest.Adler32        (adler32)
+import Data.Serialize             (runPut, putWord32le)
+import Happstack.Server           (ToMessage(..), ServerMonad, Request(Request, rqUri), Response, askRq)
+import Language.Javascript.JMacro (JStat(..), renderJs, renderPrefixJs, jmacro, jLam, toStat)
+import Text.PrettyPrint           (Style(mode), Mode(OneLineMode), style, renderStyle)
+
+lineStyle :: Style
+lineStyle = style { mode = OneLineMode }
+
+mkId :: String -> String
+mkId = S.unpack
+     . S.map dollar
+     . S.takeWhile (/= '=')
+     . encode
+     . B.dropWhile (== 0)
+     . runPut
+     . putWord32le
+     . adler32
+     . S.pack
+  where
+    dollar '-' = '$'
+    dollar c   = c
+
+data PrefixedJStat = PrefixedJStat String JStat
+
 instance ToMessage JStat where
-    toContentType _  = S.pack "text/javascript; charset=UTF-8"
-    toMessage     js = LB.fromString . renderStyle (style { mode = OneLineMode }) . renderJs $ js
+    toContentType _ = S.pack "text/javascript; charset=UTF-8"
+    toMessage    js =
+        LB.fromString . renderStyle lineStyle . renderJs $ scoped
+      where
+        scoped = [jmacro| (function { `(js)`; })(); |]
+
+instance ToMessage PrefixedJStat where
+    toContentType _ = S.pack "text/javascript; charset=UTF-8"
+    toMessage (PrefixedJStat prefix js) =
+        LB.fromString . renderStyle lineStyle . renderPrefixJs (mkId prefix) $ js
+
+-- | Render a 'JStat' into a 'Response', saturating the variable names with
+-- a hash computed from the 'rqUri'.  Unlike the 'ToMessage' instance for
+-- @JStat@, this doesn't wrap the statements in a function and so the
+-- workaround for global unhygienic names isn't necessary.  On the other
+-- hand, generated variable names are a bit longer.
+jmResponse :: ServerMonad m => JStat -> m Response
+jmResponse jstat =
+    do Request{rqUri = uri} <- askRq
+       return . toResponse $ PrefixedJStat uri jstat
diff --git a/happstack-jmacro.cabal b/happstack-jmacro.cabal
--- a/happstack-jmacro.cabal
+++ b/happstack-jmacro.cabal
@@ -1,5 +1,5 @@
 Name:                happstack-jmacro
-Version:             7.0.0
+Version:             7.0.1
 Synopsis:            Support for using JMacro with Happstack
 Homepage:            http://www.happstack.com/
 License:             BSD3
@@ -16,9 +16,12 @@
 Library
   Exposed-modules:     Happstack.Server.JMacro
   Build-depends:
-     base             >4 && <5,
-     bytestring       == 0.9.*,
-     jmacro           == 0.5.*,
-     happstack-server >= 6.4 && <7.1,
-     pretty           == 1.0.* || == 1.1.*,
-     utf8-string      == 0.3.*
+     base              >4 && <5,
+     base64-bytestring == 0.1.*,
+     bytestring        == 0.9.*,
+     cereal            == 0.3.*,
+     digest            == 0.0.*,
+     happstack-server  >= 6.4 && <7.1,
+     jmacro            == 0.5.*,
+     pretty            == 1.0.* || == 1.1.*,
+     utf8-string       == 0.3.*