diff --git a/extensions/setup.py b/extensions/setup.py
index 417b3fdd132c..4a0b8aea196d 100644
--- a/extensions/setup.py
+++ b/extensions/setup.py
@@ -17,7 +17,6 @@
     'Environment :: Console',
     'Intended Audience :: Developers',
     'License :: OSI Approved :: MIT License',
-    'Operating System :: POSIX',
     'Programming Language :: Python :: 2',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
@@ -37,7 +36,6 @@
     author_email='jukka.lehtosalo@iki.fi',
     url='http://www.mypy-lang.org/',
     license='MIT License',
-    platforms=['POSIX'],
     py_modules=['mypy_extensions'],
     classifiers=classifiers,
     install_requires=[
diff --git a/setup.py b/setup.py
index 1bd24ab9a12c..9eb12380d22a 100644
--- a/setup.py
+++ b/setup.py
@@ -82,7 +82,6 @@ def run(self):
     'Environment :: Console',
     'Intended Audience :: Developers',
     'License :: OSI Approved :: MIT License',
-    'Operating System :: POSIX',
     'Programming Language :: Python :: 3',
     'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
@@ -98,7 +97,6 @@ def run(self):
       author_email='jukka.lehtosalo@iki.fi',
       url='http://www.mypy-lang.org/',
       license='MIT License',
-      platforms=['POSIX'],
       py_modules=[],
       packages=['mypy', 'mypy.test', 'mypy.server', 'mypy.plugins'],
       entry_points={'console_scripts': ['mypy=mypy.__main__:console_entry',