diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.20151028
+
+* Turn off `-threaded` option for Windows 64bit
+
 ## 1.20150921
 
 * UDP relay on server
diff --git a/shadowsocks.cabal b/shadowsocks.cabal
--- a/shadowsocks.cabal
+++ b/shadowsocks.cabal
@@ -1,5 +1,5 @@
 name:                shadowsocks
-version:             1.20150921
+version:             1.20151028
 synopsis:            A fast SOCKS5 proxy that help you get through firewalls
 description:
     Shadowsocks implemented in Haskell. Original python version: <https://github.com/clowwindy/shadowsocks>
@@ -22,7 +22,10 @@
 
 executable sslocal
   main-is:              local.hs
-  ghc-options:          -Wall -fno-warn-unused-do-bind -O2 -threaded
+  if os(windows) && arch(x86_64)
+    ghc-options:          -Wall -fno-warn-unused-do-bind -O2
+  else
+    ghc-options:          -Wall -fno-warn-unused-do-bind -O2 -threaded
   other-modules:        Shadowsocks.Encrypt,
                         Shadowsocks.Util
   other-extensions:     OverloadedStrings, DeriveGeneric
@@ -44,7 +47,10 @@
 
 executable ssserver
   main-is:              server.hs
-  ghc-options:          -Wall -fno-warn-unused-do-bind -O2 -threaded
+  if os(windows) && arch(x86_64)
+    ghc-options:          -Wall -fno-warn-unused-do-bind -O2
+  else
+    ghc-options:          -Wall -fno-warn-unused-do-bind -O2 -threaded
   other-modules:        Shadowsocks.Encrypt,
                         Shadowsocks.Util
   other-extensions:     OverloadedStrings, DeriveGeneric