diff --git a/README b/README
index 66efaef25..5eee35518 100644
--- a/README
+++ b/README
@@ -72,12 +72,13 @@ gcc make python-dev python-twisted python-nevow python-pyopenssl".
 
  + Python setuptools (build and distribution tool)
 
-   Note: The build process will automatically download and install
-   setuptools if it is not present.  However, if an old, incompatible
-   version of setuptools (< v0.6c6) is present, then the build will fail.
-   Therefore, if the build fails due to setuptools not being compatible,
-   you can either upgrade or uninstall your version of setuptools and try
-   again.
+   Note: The build process will automatically download and install setuptools
+   if it is not present.  However, if an old, incompatible version of
+   setuptools is present (< v0.6c6 on Cygwin, or < v0.6a9 on other
+   platforms), then the build will fail.
+
+   So if the build fails due to setuptools not being compatible, you can
+   either upgrade or uninstall your version of setuptools and try again.
 
    http://peak.telecommunity.com/DevCenter/EasyInstall#installation-instructions
 
diff --git a/src/simplejson/setup.py b/src/simplejson/setup.py
index ac1892203..92c92709e 100644
--- a/src/simplejson/setup.py
+++ b/src/simplejson/setup.py
@@ -1,7 +1,11 @@
 #!/usr/bin/env python
 
 import ez_setup
-ez_setup.use_setuptools(min_version="0.6c6")
+if 'cygwin' in sys.platform.lower():
+    min_version='0.6c6'
+else:
+    min_version='0.6a9'
+ez_setup.use_setuptools(min_version=min_version)
 
 from setuptools import setup, find_packages, Extension, Feature
 from distutils.command.build_ext import build_ext
diff --git a/src/zfec/setup.py b/src/zfec/setup.py
index 8f4e31fe6..24a16e35a 100644
--- a/src/zfec/setup.py
+++ b/src/zfec/setup.py
@@ -20,7 +20,12 @@
 # http://allmydata.com/.
 
 from ez_setup import use_setuptools
-use_setuptools(min_version='0.6c6')
+import sys
+if 'cygwin' in sys.platform.lower():
+    min_version='0.6c6'
+else:
+    min_version='0.6a9'
+use_setuptools(min_version=min_version)
 
 from setuptools import Extension, find_packages, setup