diff --git a/setup/extensions.py b/setup/extensions.py
index 6e3c7e4836..12c1e435c3 100644
--- a/setup/extensions.py
+++ b/setup/extensions.py
@@ -6,7 +6,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import textwrap, os, shlex, subprocess, glob, shutil
+import textwrap, os, shlex, subprocess, glob, shutil, sys
 from distutils import sysconfig
 from multiprocessing import cpu_count
 
@@ -21,6 +21,7 @@ from setup.build_environment import (chmlib_inc_dirs,
         zlib_libs, zlib_lib_dirs, zlib_inc_dirs)
 MT
 isunix = islinux or isosx or isbsd
+is64bit = sys.maxsize > 2**32
 
 make = 'make' if isunix else NMAKE
 
@@ -278,6 +279,8 @@ if iswindows:
     ldflags = '/DLL /nologo /INCREMENTAL:NO /NODEFAULTLIB:libcmt.lib'.split()
     #cflags = '/c /nologo /Ox /MD /W3 /EHsc /Zi'.split()
     #ldflags = '/DLL /nologo /INCREMENTAL:NO /DEBUG'.split()
+    if is64bit:
+        cflags.append('/GS-')
 
     for p in win_inc:
         cflags.append('-I'+p)
diff --git a/setup/installer/windows/notes.rst b/setup/installer/windows/notes.rst
index 84300f6804..b4c4c9c09e 100644
--- a/setup/installer/windows/notes.rst
+++ b/setup/installer/windows/notes.rst
@@ -163,7 +163,7 @@ Now, run configure and make::
 
 -no-plugin-manifests is needed so that loading the plugins does not fail looking for the CRT assembly
 
-    configure -ltcg -opensource -release -qt-zlib -qt-libmng -qt-libpng -qt-libtiff -qt-libjpeg -release -platform win32-msvc2008 -no-qt3support -webkit -xmlpatterns -no-phonon -no-style-plastique -no-style-cleanlooks -no-style-motif -no-style-cde -no-declarative -no-scripttools -no-audio-backend -no-multimedia -no-dbus -no-openvg -no-opengl -no-qt3support -confirm-license -nomake examples -nomake demos -nomake docs -no-plugin-manifests -openssl -I $OPENSSL_DIR/include -L $OPENSSL_DIR/lib && nmake
+    ./configure.exe -ltcg -opensource -release -qt-zlib -qt-libmng -qt-libpng -qt-libtiff -qt-libjpeg -release -platform win32-msvc2008 -no-qt3support -webkit -xmlpatterns -no-phonon -no-style-plastique -no-style-cleanlooks -no-style-motif -no-style-cde -no-declarative -no-scripttools -no-audio-backend -no-multimedia -no-dbus -no-openvg -no-opengl -no-qt3support -confirm-license -nomake examples -nomake demos -nomake docs -nomake tools -no-plugin-manifests -openssl -I $OPENSSL_DIR/include -L $OPENSSL_DIR/lib && nmake
 
 Add the path to the bin folder inside the Qt dir to your system PATH.