diff -up tornado-4.4.2/setup.py.cert tornado-4.4.2/setup.py --- tornado-4.4.2/setup.py.cert 2016-09-30 16:43:58.000000000 -0600 +++ tornado-4.4.2/setup.py 2016-10-02 19:55:25.645685022 -0600 @@ -133,10 +133,6 @@ if setuptools is not None: install_requires.append('backports.ssl_match_hostname') if sys.version_info < (3, 4): install_requires.append('singledispatch') - # Certifi is also optional on 2.7.9+, although making our dependencies - # conditional on micro version numbers seems like a bad idea - # until we have more declarative metadata. - install_requires.append('certifi') if sys.version_info < (3, 5): install_requires.append('backports_abc>=0.4') kwargs['install_requires'] = install_requires diff -up tornado-4.4.2/tornado/simple_httpclient.py.cert tornado-4.4.2/tornado/simple_httpclient.py --- tornado-4.4.2/tornado/simple_httpclient.py.cert 2016-09-30 16:41:19.000000000 -0600 +++ tornado-4.4.2/tornado/simple_httpclient.py 2016-10-02 19:55:25.646685029 -0600 @@ -1,4 +1,3 @@ -#!/usr/bin/env python from __future__ import absolute_import, division, print_function, with_statement from tornado.escape import utf8, _unicode @@ -34,17 +33,8 @@ except ImportError: # ssl is not available on Google App Engine. ssl = None -try: - import certifi -except ImportError: - certifi = None - - def _default_ca_certs(): - if certifi is None: - raise Exception("The 'certifi' package is required to use https " - "in simple_httpclient") - return certifi.where() + return '/etc/pki/tls/cert.pem' class SimpleAsyncHTTPClient(AsyncHTTPClient):