diff --git a/lib/platforms.nix b/lib/platforms.nix
index 44a56b659c72..067670c6b3e7 100644
--- a/lib/platforms.nix
+++ b/lib/platforms.nix
@@ -7,7 +7,7 @@ rec {
   freebsd = ["i686-freebsd" "x86_64-freebsd"];
   openbsd = ["i686-openbsd" "x86_64-openbsd"];
   netbsd = ["i686-netbsd" "x86_64-netbsd"];
-  cygwin = ["i686-cygwin"];
+  cygwin = ["i686-cygwin" "x86_64-cygwin"];
   unix = linux ++ darwin ++ freebsd ++ openbsd;
   all = linux ++ darwin ++ cygwin ++ freebsd ++ openbsd;
   none = [];
diff --git a/pkgs/development/interpreters/perl/5.16/default.nix b/pkgs/development/interpreters/perl/5.16/default.nix
index 600884db5e67..a01d7b2a86b2 100644
--- a/pkgs/development/interpreters/perl/5.16/default.nix
+++ b/pkgs/development/interpreters/perl/5.16/default.nix
@@ -54,6 +54,12 @@ stdenv.mkDerivation rec {
       ${optionalString stdenv.isArm ''
         configureFlagsArray=(-Dldflags="-lm -lrt")
       ''}
+      
+      ${optionalString stdenv.isCygwin ''
+        cp cygwin/cygwin.c{,.bak}
+        echo "#define PERLIO_NOT_STDIO 0" > tmp
+        cat tmp cygwin/cygwin.c.bak > cygwin/cygwin.c
+      ''}
     '';
 
   preBuild = optionalString (!(stdenv ? gcc && stdenv.gcc.nativeTools))
@@ -64,5 +70,6 @@ stdenv.mkDerivation rec {
 
   setupHook = ./setup-hook.sh;
 
+  doCheck = stdenv.isLinux;
   passthru.libPrefix = "lib/perl5/site_perl";
 }
diff --git a/pkgs/development/libraries/openssl/default.nix b/pkgs/development/libraries/openssl/default.nix
index 8c88df984f05..c972635c9c72 100644
--- a/pkgs/development/libraries/openssl/default.nix
+++ b/pkgs/development/libraries/openssl/default.nix
@@ -60,7 +60,12 @@ stdenv.mkDerivation {
     else "./config";
 
   configureFlags = "shared --libdir=lib --openssldir=etc/ssl" +
-    stdenv.lib.optionalString withCryptodev " -DHAVE_CRYPTODEV -DUSE_CRYPTODEV_DIGESTS";
+    stdenv.lib.optionalString withCryptodev " -DHAVE_CRYPTODEV -DUSE_CRYPTODEV_DIGESTS" +
+    stdenv.lib.optionalString (stdenv.system == "x86_64-cygwin") " no-asm";
+
+  preBuild = stdenv.lib.optionalString (stdenv.system == "x86_64-cygwin") ''
+    sed -i -e "s|-march=i486|-march=x86-64|g" Makefile
+  '';
 
   makeFlags = "MANDIR=$(out)/share/man";
 
diff --git a/pkgs/stdenv/generic/default.nix b/pkgs/stdenv/generic/default.nix
index 0d8355e89cc3..595307df5564 100644
--- a/pkgs/stdenv/generic/default.nix
+++ b/pkgs/stdenv/generic/default.nix
@@ -143,7 +143,8 @@ let
              || system == "x86_64-kfreebsd-gnu";
       isSunOS = system == "i686-solaris"
              || system == "x86_64-solaris";
-      isCygwin = system == "i686-cygwin";
+      isCygwin = system == "i686-cygwin"
+              || system == "x86_64-cygwin";
       isFreeBSD = system == "i686-freebsd"
               || system == "x86_64-freebsd";
       isOpenBSD = system == "i686-openbsd"