diff --git a/yesod.cabal b/yesod.cabal
--- a/yesod.cabal
+++ b/yesod.cabal
@@ -1,5 +1,5 @@
 name:            yesod
-version:         1.2.0
+version:         1.2.0.1
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>
@@ -18,6 +18,9 @@
 homepage:        http://www.yesodweb.com/
 
 library
+    if os(windows)
+        cpp-options: -DWINDOWS
+
     build-depends:   base                      >= 4.3      && < 5
                    , yesod-core                >= 1.2      && < 1.3
                    , yesod-auth                >= 1.2      && < 1.3