diff --git a/setup.py b/setup.py
index 60c7df4..d303cb3 100644
--- a/setup.py
+++ b/setup.py
@@ -19,46 +19,46 @@
 
 
 DEPENDENCIES = (
-    'cachetools>=2.0.0,<3.2',
-    'pyasn1-modules>=0.2.1',
-    'rsa>=3.1.4,<4.1',
-    'setuptools>=40.3.0',
-    'six>=1.9.0',
+    "cachetools>=2.0.0,<3.2",
+    "pyasn1-modules>=0.2.1",
+    "rsa>=3.1.4,<4.1",
+    "setuptools>=40.3.0",
+    "six>=1.9.0",
 )
 
 
-with io.open('README.rst', 'r') as fh:
+with io.open("README.rst", "r") as fh:
     long_description = fh.read()
 
 setup(
-    name='google-auth',
-    version='1.6.3',
-    author='Google Cloud Platform',
-    author_email='jonwayne+google-auth@google.com',
-    description='Google Authentication Library',
+    name="google-auth",
+    version="1.6.3",
+    author="Google Cloud Platform",
+    author_email="jonwayne+google-auth@google.com",
+    description="Google Authentication Library",
     long_description=long_description,
-    url='https://github.com/GoogleCloudPlatform/google-auth-library-python',
-    packages=find_packages(exclude=('tests*', 'system_tests*')),
-    namespace_packages=('google',),
+    url="https://github.com/GoogleCloudPlatform/google-auth-library-python",
+    packages=find_packages(exclude=("tests*", "system_tests*")),
+    namespace_packages=("google",),
     install_requires=DEPENDENCIES,
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*',
-    license='Apache 2.0',
-    keywords='google auth oauth client',
+    python_requires=">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*",
+    license="Apache 2.0",
+    keywords="google auth oauth client",
     classifiers=[
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
-        'Development Status :: 5 - Production/Stable',
-        'Intended Audience :: Developers',
-        'License :: OSI Approved :: Apache Software License',
-        'Operating System :: POSIX',
-        'Operating System :: Microsoft :: Windows',
-        'Operating System :: MacOS :: MacOS X',
-        'Operating System :: OS Independent',
-        'Topic :: Internet :: WWW/HTTP',
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.4",
+        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
+        "Development Status :: 5 - Production/Stable",
+        "Intended Audience :: Developers",
+        "License :: OSI Approved :: Apache Software License",
+        "Operating System :: POSIX",
+        "Operating System :: Microsoft :: Windows",
+        "Operating System :: MacOS :: MacOS X",
+        "Operating System :: OS Independent",
+        "Topic :: Internet :: WWW/HTTP",
     ],
 )