diff --git a/.travis.yml b/.travis.yml
index 35666d8e6..42b8d679d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,16 +25,12 @@ matrix:
       addons:
     - python: "2.7"
       env: TOXENV=lint
-    - python: "2.6"
-      env: TOXENV=py26
-      sudo: required
-      services: docker
     - python: "2.7"
       env: TOXENV=py27-oldest
       sudo: required
       services: docker
-    - python: "3.3"
-      env: TOXENV=py33
+    - python: "3.4"
+      env: TOXENV=py34
       sudo: required
       services: docker
     - python: "3.6"
diff --git a/acme/acme/__init__.py b/acme/acme/__init__.py
index 5850fa955..e8a0b16a8 100644
--- a/acme/acme/__init__.py
+++ b/acme/acme/__init__.py
@@ -10,13 +10,3 @@ supported version: `draft-ietf-acme-01`_.
   https://github.com/ietf-wg-acme/acme/tree/draft-ietf-acme-acme-01
 
 """
-import sys
-import warnings
-
-for (major, minor) in [(2, 6), (3, 3)]:
-    if sys.version_info[:2] == (major, minor):
-        warnings.warn(
-                "Python {0}.{1} support will be dropped in the next release of "
-                "acme. Please upgrade your Python version.".format(major, minor),
-                DeprecationWarning,
-        ) #pragma: no cover
diff --git a/acme/acme/crypto_util.py b/acme/acme/crypto_util.py
index f13c5109c..07b55ae33 100644
--- a/acme/acme/crypto_util.py
+++ b/acme/acme/crypto_util.py
@@ -5,7 +5,6 @@ import logging
 import os
 import re
 import socket
-import sys
 
 import OpenSSL
 import josepy as jose
@@ -132,8 +131,7 @@ def probe_sni(name, host, port=443, timeout=300,
     context = OpenSSL.SSL.Context(method)
     context.set_timeout(timeout)
 
-    socket_kwargs = {} if sys.version_info < (2, 7) else {
-        'source_address': source_address}
+    socket_kwargs = {'source_address': source_address}
 
     host_protocol_agnostic = None if host == '::' or host == '0' else host
 
diff --git a/acme/acme/crypto_util_test.py b/acme/acme/crypto_util_test.py
index e8dd3b20c..3874ba9d9 100644
--- a/acme/acme/crypto_util_test.py
+++ b/acme/acme/crypto_util_test.py
@@ -194,9 +194,9 @@ class MakeCSRTest(unittest.TestCase):
         self.assertTrue(b'--END CERTIFICATE REQUEST--' in csr_pem)
         csr = OpenSSL.crypto.load_certificate_request(
             OpenSSL.crypto.FILETYPE_PEM, csr_pem)
-        # In pyopenssl 0.13 (used with TOXENV=py26-oldest and py27-oldest), csr
-        # objects don't have a get_extensions() method, so we skip this test if
-        # the method isn't available.
+        # In pyopenssl 0.13 (used with TOXENV=py27-oldest), csr objects don't
+        # have a get_extensions() method, so we skip this test if the method
+        # isn't available.
         if hasattr(csr, 'get_extensions'):
             self.assertEquals(len(csr.get_extensions()), 1)
             self.assertEquals(csr.get_extensions()[0].get_data(),
@@ -212,9 +212,9 @@ class MakeCSRTest(unittest.TestCase):
         csr = OpenSSL.crypto.load_certificate_request(
             OpenSSL.crypto.FILETYPE_PEM, csr_pem)
 
-        # In pyopenssl 0.13 (used with TOXENV=py26-oldest and py27-oldest), csr
-        # objects don't have a get_extensions() method, so we skip this test if
-        # the method isn't available.
+        # In pyopenssl 0.13 (used with TOXENV=py27-oldest), csr objects don't
+        # have a get_extensions() method, so we skip this test if the method
+        # isn't available.
         if hasattr(csr, 'get_extensions'):
             self.assertEquals(len(csr.get_extensions()), 2)
             # NOTE: Ideally we would filter by the TLS Feature OID, but
diff --git a/acme/setup.py b/acme/setup.py
index 51bbf0f71..071b56ab3 100644
--- a/acme/setup.py
+++ b/acme/setup.py
@@ -23,13 +23,6 @@ install_requires = [
     'six>=1.9.0',  # needed for python_2_unicode_compatible
 ]
 
-# env markers cause problems with older pip and setuptools
-if sys.version_info < (2, 7):
-    install_requires.extend([
-        'argparse',
-        'ordereddict',
-    ])
-
 dev_extras = [
     'pytest',
     'pytest-xdist',
@@ -50,16 +43,15 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-apache/setup.py b/certbot-apache/setup.py
index 76d7f5ca5..336233bd4 100644
--- a/certbot-apache/setup.py
+++ b/certbot-apache/setup.py
@@ -30,6 +30,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -38,10 +39,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-compatibility-test/setup.py b/certbot-compatibility-test/setup.py
index 8f9f897cf..861921ef7 100644
--- a/certbot-compatibility-test/setup.py
+++ b/certbot-compatibility-test/setup.py
@@ -34,16 +34,15 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-cloudflare/setup.py b/certbot-dns-cloudflare/setup.py
index e1b84d1be..e5687a9f5 100644
--- a/certbot-dns-cloudflare/setup.py
+++ b/certbot-dns-cloudflare/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -37,10 +38,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-cloudxns/setup.py b/certbot-dns-cloudxns/setup.py
index 53ceb58ea..0ef31a90c 100644
--- a/certbot-dns-cloudxns/setup.py
+++ b/certbot-dns-cloudxns/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -39,7 +40,6 @@ setup(
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-digitalocean/setup.py b/certbot-dns-digitalocean/setup.py
index 3330bdd67..11c2aea24 100644
--- a/certbot-dns-digitalocean/setup.py
+++ b/certbot-dns-digitalocean/setup.py
@@ -30,6 +30,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -38,10 +39,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-dnsimple/setup.py b/certbot-dns-dnsimple/setup.py
index 00a3c032a..414a058fa 100644
--- a/certbot-dns-dnsimple/setup.py
+++ b/certbot-dns-dnsimple/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -39,7 +40,6 @@ setup(
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-dnsmadeeasy/setup.py b/certbot-dns-dnsmadeeasy/setup.py
index 36119ade0..18d773347 100644
--- a/certbot-dns-dnsmadeeasy/setup.py
+++ b/certbot-dns-dnsmadeeasy/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -39,7 +40,6 @@ setup(
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-google/setup.py b/certbot-dns-google/setup.py
index 10fccd1ea..d5def1bf9 100644
--- a/certbot-dns-google/setup.py
+++ b/certbot-dns-google/setup.py
@@ -34,6 +34,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -42,10 +43,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-luadns/setup.py b/certbot-dns-luadns/setup.py
index b094e1818..13fa742d5 100644
--- a/certbot-dns-luadns/setup.py
+++ b/certbot-dns-luadns/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -39,7 +40,6 @@ setup(
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-nsone/setup.py b/certbot-dns-nsone/setup.py
index e777d821b..01c9579c1 100644
--- a/certbot-dns-nsone/setup.py
+++ b/certbot-dns-nsone/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -39,7 +40,6 @@ setup(
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-rfc2136/setup.py b/certbot-dns-rfc2136/setup.py
index 6fc6dca73..64b126595 100644
--- a/certbot-dns-rfc2136/setup.py
+++ b/certbot-dns-rfc2136/setup.py
@@ -29,6 +29,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -37,10 +38,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-dns-route53/setup.py b/certbot-dns-route53/setup.py
index 0fbeab31b..e45343f79 100644
--- a/certbot-dns-route53/setup.py
+++ b/certbot-dns-route53/setup.py
@@ -22,6 +22,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -30,10 +31,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot-nginx/setup.py b/certbot-nginx/setup.py
index a84efe2c3..96f8b834d 100644
--- a/certbot-nginx/setup.py
+++ b/certbot-nginx/setup.py
@@ -30,6 +30,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Plugins',
@@ -38,10 +39,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/certbot/log.py b/certbot/log.py
index f7c7b126c..e0d2e8f11 100644
--- a/certbot/log.py
+++ b/certbot/log.py
@@ -165,12 +165,7 @@ class ColoredStreamHandler(logging.StreamHandler):
 
     """
     def __init__(self, stream=None):
-        # logging handlers use old style classes in Python 2.6 so
-        # super() cannot be used
-        if sys.version_info < (2, 7):  # pragma: no cover
-            logging.StreamHandler.__init__(self, stream)
-        else:
-            super(ColoredStreamHandler, self).__init__(stream)
+        super(ColoredStreamHandler, self).__init__(stream)
         self.colored = (sys.stderr.isatty() if stream is None else
                         stream.isatty())
         self.red_level = logging.WARNING
@@ -184,9 +179,7 @@ class ColoredStreamHandler(logging.StreamHandler):
         :rtype: str
 
         """
-        out = (logging.StreamHandler.format(self, record)
-               if sys.version_info < (2, 7)
-               else super(ColoredStreamHandler, self).format(record))
+        out = super(ColoredStreamHandler, self).format(record)
         if self.colored and record.levelno >= self.red_level:
             return ''.join((util.ANSI_SGR_RED, out, util.ANSI_SGR_RESET))
         else:
@@ -203,23 +196,14 @@ class MemoryHandler(logging.handlers.MemoryHandler):
     def __init__(self, target=None):
         # capacity doesn't matter because should_flush() is overridden
         capacity = float('inf')
-        # logging handlers use old style classes in Python 2.6 so
-        # super() cannot be used
-        if sys.version_info < (2, 7):  # pragma: no cover
-            logging.handlers.MemoryHandler.__init__(
-                self, capacity, target=target)
-        else:
-            super(MemoryHandler, self).__init__(capacity, target=target)
+        super(MemoryHandler, self).__init__(capacity, target=target)
 
     def close(self):
         """Close the memory handler, but don't set the target to None."""
         # This allows the logging module which may only have a weak
         # reference to the target handler to properly flush and close it.
         target = self.target
-        if sys.version_info < (2, 7):  # pragma: no cover
-            logging.handlers.MemoryHandler.close(self)
-        else:
-            super(MemoryHandler, self).close()
+        super(MemoryHandler, self).close()
         self.target = target
 
     def flush(self, force=False):  # pylint: disable=arguments-differ
@@ -233,10 +217,7 @@ class MemoryHandler(logging.handlers.MemoryHandler):
         # This method allows flush() calls in logging.shutdown to be a
         # noop so we can control when this handler is flushed.
         if force:
-            if sys.version_info < (2, 7):  # pragma: no cover
-                logging.handlers.MemoryHandler.flush(self)
-            else:
-                super(MemoryHandler, self).flush()
+            super(MemoryHandler, self).flush()
 
     def shouldFlush(self, record):
         """Should the buffer be automatically flushed?
@@ -262,12 +243,7 @@ class TempHandler(logging.StreamHandler):
     """
     def __init__(self):
         stream = tempfile.NamedTemporaryFile('w', delete=False)
-        # logging handlers use old style classes in Python 2.6 so
-        # super() cannot be used
-        if sys.version_info < (2, 7):  # pragma: no cover
-            logging.StreamHandler.__init__(self, stream)
-        else:
-            super(TempHandler, self).__init__(stream)
+        super(TempHandler, self).__init__(stream)
         self.path = stream.name
         self._delete = True
 
@@ -278,12 +254,7 @@ class TempHandler(logging.StreamHandler):
 
         """
         self._delete = False
-        # logging handlers use old style classes in Python 2.6 so
-        # super() cannot be used
-        if sys.version_info < (2, 7):  # pragma: no cover
-            logging.StreamHandler.emit(self, record)
-        else:
-            super(TempHandler, self).emit(record)
+        super(TempHandler, self).emit(record)
 
     def close(self):
         """Close the handler and the temporary log file.
@@ -299,10 +270,7 @@ class TempHandler(logging.StreamHandler):
             if self._delete:
                 os.remove(self.path)
             self._delete = False
-            if sys.version_info < (2, 7):  # pragma: no cover
-                logging.StreamHandler.close(self)
-            else:
-                super(TempHandler, self).close()
+            super(TempHandler, self).close()
         finally:
             self.release()
 
diff --git a/certbot/main.py b/certbot/main.py
index eff4c9c8f..33c7730c6 100644
--- a/certbot/main.py
+++ b/certbot/main.py
@@ -5,7 +5,6 @@ import functools
 import logging.handlers
 import os
 import sys
-import warnings
 
 import configobj
 import josepy as jose
@@ -1256,17 +1255,6 @@ def main(cli_args=sys.argv[1:]):
         # Let plugins_cmd be run as un-privileged user.
         if config.func != plugins_cmd:
             raise
-    deprecation_fmt = (
-        "Python %s.%s support will be dropped in the next "
-        "release of Certbot - please upgrade your Python version.")
-    # We use the warnings system for Python 2.6 and logging for Python 3
-    # because DeprecationWarnings are only reported by default in Python <= 2.6
-    # and warnings can be disabled by the user.
-    if sys.version_info[:2] == (2, 6):
-        warning = deprecation_fmt % sys.version_info[:2]
-        warnings.warn(warning, DeprecationWarning)
-    elif sys.version_info[:2] == (3, 3):
-        logger.warning(deprecation_fmt, *sys.version_info[:2])
 
     set_displayer(config)
 
diff --git a/certbot/plugins/disco.py b/certbot/plugins/disco.py
index 37baf98f7..5a7e07ec0 100644
--- a/certbot/plugins/disco.py
+++ b/certbot/plugins/disco.py
@@ -5,6 +5,8 @@ import logging
 import pkg_resources
 import six
 
+from collections import OrderedDict
+
 import zope.interface
 import zope.interface.verify
 
@@ -12,12 +14,6 @@ from certbot import constants
 from certbot import errors
 from certbot import interfaces
 
-try:
-    from collections import OrderedDict
-except ImportError:  # pragma: no cover
-    # OrderedDict was added in Python 2.7
-    from ordereddict import OrderedDict  # pylint: disable=import-error
-
 
 logger = logging.getLogger(__name__)
 
diff --git a/certbot/util.py b/certbot/util.py
index 70f402a72..f47c5da9c 100644
--- a/certbot/util.py
+++ b/certbot/util.py
@@ -16,18 +16,14 @@ import stat
 import subprocess
 import sys
 
+from collections import OrderedDict
+
 import configargparse
 
 from certbot import constants
 from certbot import errors
 from certbot import lock
 
-try:
-    from collections import OrderedDict
-except ImportError:  # pragma: no cover
-    # OrderedDict was added in Python 2.7
-    from ordereddict import OrderedDict  # pylint: disable=import-error
-
 
 logger = logging.getLogger(__name__)
 
diff --git a/docs/contributing.rst b/docs/contributing.rst
index 83b607e15..654528e3d 100644
--- a/docs/contributing.rst
+++ b/docs/contributing.rst
@@ -422,7 +422,7 @@ OS-level dependencies can be installed like so:
 In general...
 
 * ``sudo`` is required as a suggested way of running privileged process
-* `Python`_ 2.6/2.7 is required
+* `Python`_ 2.7 is required
 * `Augeas`_ is required for the Python bindings
 * ``virtualenv`` and ``pip`` are used for managing other python library
   dependencies
diff --git a/docs/install.rst b/docs/install.rst
index c18c3cdbc..aec885b62 100644
--- a/docs/install.rst
+++ b/docs/install.rst
@@ -22,7 +22,7 @@ your system.
 System Requirements
 ===================
 
-Certbot currently requires Python 2.6, 2.7, or 3.3+. By default, it requires
+Certbot currently requires Python 2.7, or 3.4+. By default, it requires
 root access in order to write to ``/etc/letsencrypt``,
 ``/var/log/letsencrypt``, ``/var/lib/letsencrypt``; to bind to ports 80 and 443
 (if you use the ``standalone`` plugin) and to read and modify webserver
diff --git a/letsencrypt-auto-source/letsencrypt-auto b/letsencrypt-auto-source/letsencrypt-auto
index c84499eab..9ff1c1386 100755
--- a/letsencrypt-auto-source/letsencrypt-auto
+++ b/letsencrypt-auto-source/letsencrypt-auto
@@ -249,7 +249,7 @@ DeprecationBootstrap() {
   fi
 }
 
-MIN_PYTHON_VERSION="2.6"
+MIN_PYTHON_VERSION="2.7"
 MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
 # digits of the python version
@@ -1240,6 +1240,7 @@ anything goes wrong, it will exit with a non-zero status code.
 from __future__ import print_function
 from distutils.version import StrictVersion
 from hashlib import sha256
+from os import environ
 from os.path import join
 from pipes import quote
 from shutil import rmtree
@@ -1273,33 +1274,32 @@ except ImportError:
     from urllib.parse import urlparse  # 3.4
 
 
-__version__ = 1, 3, 0
+__version__ = 1, 5, 0
 PIP_VERSION = '9.0.1'
+DEFAULT_INDEX_BASE = 'https://pypi.python.org'
 
 
 # wheel has a conditional dependency on argparse:
 maybe_argparse = (
-    [('https://pypi.python.org/packages/18/dd/'
-      'e617cfc3f6210ae183374cd9f6a26b20514bbb5a792af97949c5aacddf0f/'
+    [('18/dd/e617cfc3f6210ae183374cd9f6a26b20514bbb5a792af97949c5aacddf0f/'
       'argparse-1.4.0.tar.gz',
       '62b089a55be1d8949cd2bc7e0df0bddb9e028faefc8c32038cc84862aefdd6e4')]
     if version_info < (2, 7, 0) else [])
 
 
-PACKAGES = maybe_argparse + [
-    # Pip has no dependencies, as it vendors everything:
-    ('https://pypi.python.org/packages/11/b6/'
-     'abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/'
-     'pip-{0}.tar.gz'
-     .format(PIP_VERSION),
-     '09f243e1a7b461f654c26a725fa373211bb7ff17a9300058b205c61658ca940d'),
+# Pip has no dependencies, as it vendors everything:
+PIP_PACKAGE = [
+    ('11/b6/abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/'
+     'pip-{0}.tar.gz'.format(PIP_VERSION),
+     '09f243e1a7b461f654c26a725fa373211bb7ff17a9300058b205c61658ca940d')]
+
+
+OTHER_PACKAGES = maybe_argparse + [
     # This version of setuptools has only optional dependencies:
-    ('https://pypi.python.org/packages/69/65/'
-     '4c544cde88d4d876cdf5cbc5f3f15d02646477756d89547e9a7ecd6afa76/'
-     'setuptools-20.2.2.tar.gz',
-     '24fcfc15364a9fe09a220f37d2dcedc849795e3de3e4b393ee988e66a9cbd85a'),
-    ('https://pypi.python.org/packages/c9/1d/'
-     'bd19e691fd4cfe908c76c429fe6e4436c9e83583c4414b54f6c85471954a/'
+    ('59/88/2f3990916931a5de6fa9706d6d75eb32ee8b78627bb2abaab7ed9e6d0622/'
+     'setuptools-29.0.1.tar.gz',
+     'b539118819a4857378398891fa5366e090690e46b3e41421a1e07d6e9fd8feb0'),
+    ('c9/1d/bd19e691fd4cfe908c76c429fe6e4436c9e83583c4414b54f6c85471954a/'
      'wheel-0.29.0.tar.gz',
      '1ebb8ad7e26b448e9caa4773d2357849bf80ff9e313964bcaf79cbf0201a1648')
 ]
@@ -1320,12 +1320,13 @@ def hashed_download(url, temp, digest):
     # >=2.7.9 verifies HTTPS certs itself, and, in any case, the cert
     # authenticity has only privacy (not arbitrary code execution)
     # implications, since we're checking hashes.
-    def opener():
+    def opener(using_https=True):
         opener = build_opener(HTTPSHandler())
-        # Strip out HTTPHandler to prevent MITM spoof:
-        for handler in opener.handlers:
-            if isinstance(handler, HTTPHandler):
-                opener.handlers.remove(handler)
+        if using_https:
+            # Strip out HTTPHandler to prevent MITM spoof:
+            for handler in opener.handlers:
+                if isinstance(handler, HTTPHandler):
+                    opener.handlers.remove(handler)
         return opener
 
     def read_chunks(response, chunk_size):
@@ -1335,8 +1336,9 @@ def hashed_download(url, temp, digest):
                 break
             yield chunk
 
-    response = opener().open(url)
-    path = join(temp, urlparse(url).path.split('/')[-1])
+    parsed_url = urlparse(url)
+    response = opener(using_https=parsed_url.scheme == 'https').open(url)
+    path = join(temp, parsed_url.path.split('/')[-1])
     actual_hash = sha256()
     with open(path, 'wb') as file:
         for chunk in read_chunks(response, 4096):
@@ -1349,6 +1351,24 @@ def hashed_download(url, temp, digest):
     return path
 
 
+def get_index_base():
+    """Return the URL to the dir containing the "packages" folder.
+
+    Try to wring something out of PIP_INDEX_URL, if set. Hack "/simple" off the
+    end if it's there; that is likely to give us the right dir.
+
+    """
+    env_var = environ.get('PIP_INDEX_URL', '').rstrip('/')
+    if env_var:
+        SIMPLE = '/simple'
+        if env_var.endswith(SIMPLE):
+            return env_var[:-len(SIMPLE)]
+        else:
+            return env_var
+    else:
+        return DEFAULT_INDEX_BASE
+
+
 def main():
     pip_version = StrictVersion(check_output(['pip', '--version'])
                                 .decode('utf-8').split()[1])
@@ -1356,17 +1376,24 @@ def main():
     if pip_version >= min_pip_version:
         return 0
     has_pip_cache = pip_version >= StrictVersion('6.0')
-
+    index_base = get_index_base()
     temp = mkdtemp(prefix='pipstrap-')
     try:
-        downloads = [hashed_download(url, temp, digest)
-                     for url, digest in PACKAGES]
-        check_output('pip install --no-index --no-deps -U ' +
-                     # Disable cache since we're not using it and it otherwise
-                     # sometimes throws permission warnings:
-                     ('--no-cache-dir ' if has_pip_cache else '') +
-                     ' '.join(quote(d) for d in downloads),
-                     shell=True)
+        # We download and install pip first, then the rest, to avoid the bug
+        # https://github.com/certbot/certbot/issues/4938.
+        pip_downloads, other_downloads = [
+            [hashed_download(index_base + '/packages/' + path,
+                             temp,
+                             digest)
+             for path, digest in packages]
+            for packages in (PIP_PACKAGE, OTHER_PACKAGES)]
+        for downloads in (pip_downloads, other_downloads):
+            check_output('pip install --no-index --no-deps -U ' +
+                         # Disable cache since we're not using it and it
+                         # otherwise sometimes throws permission warnings:
+                         ('--no-cache-dir ' if has_pip_cache else '') +
+                         ' '.join(quote(d) for d in downloads),
+                         shell=True)
     except HashError as exc:
         print(exc)
     except Exception:
diff --git a/letsencrypt-auto-source/letsencrypt-auto.template b/letsencrypt-auto-source/letsencrypt-auto.template
index 365fc6752..9d0f27009 100755
--- a/letsencrypt-auto-source/letsencrypt-auto.template
+++ b/letsencrypt-auto-source/letsencrypt-auto.template
@@ -249,7 +249,7 @@ DeprecationBootstrap() {
   fi
 }
 
-MIN_PYTHON_VERSION="2.6"
+MIN_PYTHON_VERSION="2.7"
 MIN_PYVER=$(echo "$MIN_PYTHON_VERSION" | sed 's/\.//')
 # Sets LE_PYTHON to Python version string and PYVER to the first two
 # digits of the python version
diff --git a/letsencrypt-auto-source/pieces/pipstrap.py b/letsencrypt-auto-source/pieces/pipstrap.py
index 78491b5e3..ed55b37e9 100755
--- a/letsencrypt-auto-source/pieces/pipstrap.py
+++ b/letsencrypt-auto-source/pieces/pipstrap.py
@@ -23,6 +23,7 @@ anything goes wrong, it will exit with a non-zero status code.
 from __future__ import print_function
 from distutils.version import StrictVersion
 from hashlib import sha256
+from os import environ
 from os.path import join
 from pipes import quote
 from shutil import rmtree
@@ -56,33 +57,32 @@ except ImportError:
     from urllib.parse import urlparse  # 3.4
 
 
-__version__ = 1, 3, 0
+__version__ = 1, 5, 0
 PIP_VERSION = '9.0.1'
+DEFAULT_INDEX_BASE = 'https://pypi.python.org'
 
 
 # wheel has a conditional dependency on argparse:
 maybe_argparse = (
-    [('https://pypi.python.org/packages/18/dd/'
-      'e617cfc3f6210ae183374cd9f6a26b20514bbb5a792af97949c5aacddf0f/'
+    [('18/dd/e617cfc3f6210ae183374cd9f6a26b20514bbb5a792af97949c5aacddf0f/'
       'argparse-1.4.0.tar.gz',
       '62b089a55be1d8949cd2bc7e0df0bddb9e028faefc8c32038cc84862aefdd6e4')]
     if version_info < (2, 7, 0) else [])
 
 
-PACKAGES = maybe_argparse + [
-    # Pip has no dependencies, as it vendors everything:
-    ('https://pypi.python.org/packages/11/b6/'
-     'abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/'
-     'pip-{0}.tar.gz'
-     .format(PIP_VERSION),
-     '09f243e1a7b461f654c26a725fa373211bb7ff17a9300058b205c61658ca940d'),
+# Pip has no dependencies, as it vendors everything:
+PIP_PACKAGE = [
+    ('11/b6/abcb525026a4be042b486df43905d6893fb04f05aac21c32c638e939e447/'
+     'pip-{0}.tar.gz'.format(PIP_VERSION),
+     '09f243e1a7b461f654c26a725fa373211bb7ff17a9300058b205c61658ca940d')]
+
+
+OTHER_PACKAGES = maybe_argparse + [
     # This version of setuptools has only optional dependencies:
-    ('https://pypi.python.org/packages/69/65/'
-     '4c544cde88d4d876cdf5cbc5f3f15d02646477756d89547e9a7ecd6afa76/'
-     'setuptools-20.2.2.tar.gz',
-     '24fcfc15364a9fe09a220f37d2dcedc849795e3de3e4b393ee988e66a9cbd85a'),
-    ('https://pypi.python.org/packages/c9/1d/'
-     'bd19e691fd4cfe908c76c429fe6e4436c9e83583c4414b54f6c85471954a/'
+    ('59/88/2f3990916931a5de6fa9706d6d75eb32ee8b78627bb2abaab7ed9e6d0622/'
+     'setuptools-29.0.1.tar.gz',
+     'b539118819a4857378398891fa5366e090690e46b3e41421a1e07d6e9fd8feb0'),
+    ('c9/1d/bd19e691fd4cfe908c76c429fe6e4436c9e83583c4414b54f6c85471954a/'
      'wheel-0.29.0.tar.gz',
      '1ebb8ad7e26b448e9caa4773d2357849bf80ff9e313964bcaf79cbf0201a1648')
 ]
@@ -103,12 +103,13 @@ def hashed_download(url, temp, digest):
     # >=2.7.9 verifies HTTPS certs itself, and, in any case, the cert
     # authenticity has only privacy (not arbitrary code execution)
     # implications, since we're checking hashes.
-    def opener():
+    def opener(using_https=True):
         opener = build_opener(HTTPSHandler())
-        # Strip out HTTPHandler to prevent MITM spoof:
-        for handler in opener.handlers:
-            if isinstance(handler, HTTPHandler):
-                opener.handlers.remove(handler)
+        if using_https:
+            # Strip out HTTPHandler to prevent MITM spoof:
+            for handler in opener.handlers:
+                if isinstance(handler, HTTPHandler):
+                    opener.handlers.remove(handler)
         return opener
 
     def read_chunks(response, chunk_size):
@@ -118,8 +119,9 @@ def hashed_download(url, temp, digest):
                 break
             yield chunk
 
-    response = opener().open(url)
-    path = join(temp, urlparse(url).path.split('/')[-1])
+    parsed_url = urlparse(url)
+    response = opener(using_https=parsed_url.scheme == 'https').open(url)
+    path = join(temp, parsed_url.path.split('/')[-1])
     actual_hash = sha256()
     with open(path, 'wb') as file:
         for chunk in read_chunks(response, 4096):
@@ -132,6 +134,24 @@ def hashed_download(url, temp, digest):
     return path
 
 
+def get_index_base():
+    """Return the URL to the dir containing the "packages" folder.
+
+    Try to wring something out of PIP_INDEX_URL, if set. Hack "/simple" off the
+    end if it's there; that is likely to give us the right dir.
+
+    """
+    env_var = environ.get('PIP_INDEX_URL', '').rstrip('/')
+    if env_var:
+        SIMPLE = '/simple'
+        if env_var.endswith(SIMPLE):
+            return env_var[:-len(SIMPLE)]
+        else:
+            return env_var
+    else:
+        return DEFAULT_INDEX_BASE
+
+
 def main():
     pip_version = StrictVersion(check_output(['pip', '--version'])
                                 .decode('utf-8').split()[1])
@@ -139,17 +159,24 @@ def main():
     if pip_version >= min_pip_version:
         return 0
     has_pip_cache = pip_version >= StrictVersion('6.0')
-
+    index_base = get_index_base()
     temp = mkdtemp(prefix='pipstrap-')
     try:
-        downloads = [hashed_download(url, temp, digest)
-                     for url, digest in PACKAGES]
-        check_output('pip install --no-index --no-deps -U ' +
-                     # Disable cache since we're not using it and it otherwise
-                     # sometimes throws permission warnings:
-                     ('--no-cache-dir ' if has_pip_cache else '') +
-                     ' '.join(quote(d) for d in downloads),
-                     shell=True)
+        # We download and install pip first, then the rest, to avoid the bug
+        # https://github.com/certbot/certbot/issues/4938.
+        pip_downloads, other_downloads = [
+            [hashed_download(index_base + '/packages/' + path,
+                             temp,
+                             digest)
+             for path, digest in packages]
+            for packages in (PIP_PACKAGE, OTHER_PACKAGES)]
+        for downloads in (pip_downloads, other_downloads):
+            check_output('pip install --no-index --no-deps -U ' +
+                         # Disable cache since we're not using it and it
+                         # otherwise sometimes throws permission warnings:
+                         ('--no-cache-dir ' if has_pip_cache else '') +
+                         ' '.join(quote(d) for d in downloads),
+                         shell=True)
     except HashError as exc:
         print(exc)
     except Exception:
diff --git a/letsencrypt-auto-source/tests/auto_test.py b/letsencrypt-auto-source/tests/auto_test.py
index d187452a1..8c2bfc079 100644
--- a/letsencrypt-auto-source/tests/auto_test.py
+++ b/letsencrypt-auto-source/tests/auto_test.py
@@ -287,8 +287,8 @@ class AutoTests(TestCase):
                 self.assertTrue(re.match(r'letsencrypt \d+\.\d+\.\d+',
                                 err.strip().splitlines()[-1]))
                 # Make a few assertions to test the validity of the next tests:
-                self.assertTrue('Upgrading certbot-auto ' in out)
-                self.assertTrue('Creating virtual environment...' in out)
+                self.assertIn('Upgrading certbot-auto ', out)
+                self.assertIn('Creating virtual environment...', out)
 
                 # Now we have le-auto 99.9.9  and LE 99.9.9 installed. This
                 # conveniently sets us up to test the next 2 cases.
@@ -296,8 +296,8 @@ class AutoTests(TestCase):
                 # Test when neither phase-1 upgrade nor phase-2 upgrade is
                 # needed (probably a common case):
                 out, err = run_letsencrypt_auto()
-                self.assertFalse('Upgrading certbot-auto ' in out)
-                self.assertFalse('Creating virtual environment...' in out)
+                self.assertNotIn('Upgrading certbot-auto ', out)
+                self.assertNotIn('Creating virtual environment...', out)
 
     def test_phase2_upgrade(self):
         """Test a phase-2 upgrade without a phase-1 upgrade."""
@@ -312,8 +312,8 @@ class AutoTests(TestCase):
                 # Create venv saving the correct bootstrap script version
                 out, err = run_le_auto(le_auto_path, venv_dir, base_url,
                                        PIP_FIND_LINKS=pip_find_links)
-                self.assertFalse('Upgrading certbot-auto ' in out)
-                self.assertTrue('Creating virtual environment...' in out)
+                self.assertNotIn('Upgrading certbot-auto ', out)
+                self.assertIn('Creating virtual environment...', out)
                 with open(join(venv_dir, BOOTSTRAP_FILENAME)) as f:
                     bootstrap_version = f.read()
 
@@ -329,8 +329,8 @@ class AutoTests(TestCase):
                 out, err = run_le_auto(le_auto_path, venv_dir, base_url,
                                        PIP_FIND_LINKS=pip_find_links)
 
-                self.assertFalse('Upgrading certbot-auto ' in out)
-                self.assertTrue('Creating virtual environment...' in out)
+                self.assertNotIn('Upgrading certbot-auto ', out)
+                self.assertIn('Creating virtual environment...', out)
 
     def test_openssl_failure(self):
         """Make sure we stop if the openssl signature check fails."""
diff --git a/letshelp-certbot/letshelp_certbot/apache.py b/letshelp-certbot/letshelp_certbot/apache.py
index b13057ca5..f77a6a1b0 100755
--- a/letshelp-certbot/letshelp_certbot/apache.py
+++ b/letshelp-certbot/letshelp_certbot/apache.py
@@ -5,7 +5,6 @@ from __future__ import print_function
 
 import argparse
 import atexit
-import contextlib
 import os
 import re
 import shutil
@@ -302,8 +301,7 @@ def main():
     make_and_verify_selection(args.server_root, tempdir)
 
     tarpath = os.path.join(tempdir, "config.tar.gz")
-    # contextlib.closing used for py26 support
-    with contextlib.closing(tarfile.open(tarpath, mode="w:gz")) as tar:
+    with tarfile.open(tarpath, mode="w:gz") as tar:
         tar.add(tempdir, arcname=".")
 
     # TODO: Submit tarpath
diff --git a/letshelp-certbot/setup.py b/letshelp-certbot/setup.py
index 3ce442b3e..b5be07a59 100644
--- a/letshelp-certbot/setup.py
+++ b/letshelp-certbot/setup.py
@@ -24,6 +24,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: System Administrators',
@@ -31,10 +32,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/setup.py b/setup.py
index 736ef467f..9ac1a7ee7 100644
--- a/setup.py
+++ b/setup.py
@@ -51,13 +51,6 @@ install_requires = [
     'zope.interface',
 ]
 
-# env markers cause problems with older pip and setuptools
-if sys.version_info < (2, 7):
-    install_requires.extend([
-        'argparse',
-        'ordereddict',
-    ])
-
 dev_extras = [
     # Pin astroid==1.3.5, pylint==1.4.2 as a workaround for #289
     'astroid==1.3.5',
@@ -88,6 +81,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Environment :: Console',
@@ -97,10 +91,8 @@ setup(
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
diff --git a/tests/letstest/scripts/test_tox.sh b/tests/letstest/scripts/test_tox.sh
index 4c2eb429e..84e4bcd22 100755
--- a/tests/letstest/scripts/test_tox.sh
+++ b/tests/letstest/scripts/test_tox.sh
@@ -15,10 +15,4 @@ VENV_BIN=${VENV_PATH}/bin
 
 cd letsencrypt
 ./tools/venv.sh
-PYVER=`python --version 2>&1 | cut -d" " -f 2 | cut -d. -f1,2 | sed 's/\.//'`
-
-if [ $PYVER -eq 26 ] ; then
-    venv/bin/tox -e py26
-else
-    venv/bin/tox -e py27
-fi
+venv/bin/tox -e py27
diff --git a/tests/run_http_server.py b/tests/run_http_server.py
index fd1163816..0e4f8ac79 100644
--- a/tests/run_http_server.py
+++ b/tests/run_http_server.py
@@ -3,7 +3,7 @@ import sys
 
 # Run Python's built-in HTTP server
 # Usage: python ./tests/run_http_server.py port_num
-# NOTE: This script should be compatible with 2.6, 2.7, 3.3+
+# NOTE: This script should be compatible with 2.7, 3.4+
 
 # sys.argv (port number) is passed as-is to the HTTP server module
 runpy.run_module(
diff --git a/tools/install_and_test.sh b/tools/install_and_test.sh
index 0d39e0594..f0385470b 100755
--- a/tools/install_and_test.sh
+++ b/tools/install_and_test.sh
@@ -18,10 +18,6 @@ for requirement in "$@" ; do
   pkg=$(echo $requirement | cut -f1 -d\[)  # remove any extras such as [dev]
   if [ $pkg = "." ]; then
     pkg="certbot"
-  else
-    # Work around a bug in pytest/importlib for the deprecated Python 3.3.
-    # See https://travis-ci.org/certbot/certbot/jobs/308774157#L1333.
-    pkg=$(echo "$pkg" | tr - _)
   fi
   "$(dirname $0)/pytest.sh" --pyargs $pkg
 done
diff --git a/tox.ini b/tox.ini
index 20f5cda32..971aa7631 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 
 [tox]
 skipsdist = true
-envlist = modification,py{26,33,34,35,36},cover,lint
+envlist = modification,py{34,35,36},cover,lint
 
 [base]
 # pip installs the requested packages in editable mode
@@ -14,25 +14,22 @@ pip_install = {toxinidir}/tools/pip_install_editable.sh
 # before the script moves on to the next package. All dependencies are pinned
 # to a specific version for increased stability for developers.
 install_and_test = {toxinidir}/tools/install_and_test.sh
-py26_packages =
+all_packages =
     acme[dev] \
     .[dev] \
     certbot-apache \
     certbot-dns-cloudflare \
+    certbot-dns-cloudxns \
     certbot-dns-digitalocean \
+    certbot-dns-dnsimple \
+    certbot-dns-dnsmadeeasy \
     certbot-dns-google \
+    certbot-dns-luadns \
+    certbot-dns-nsone \
     certbot-dns-rfc2136 \
     certbot-dns-route53 \
     certbot-nginx \
     letshelp-certbot
-non_py26_packages =
-    certbot-dns-cloudxns \
-    certbot-dns-dnsimple \
-    certbot-dns-dnsmadeeasy \
-    certbot-dns-luadns \
-    certbot-dns-nsone
-all_packages =
-    {[base]py26_packages} {[base]non_py26_packages}
 install_packages =
     {toxinidir}/tools/pip_install_editable.sh {[base]all_packages}
 source_paths =
@@ -54,32 +51,15 @@ source_paths =
     letshelp-certbot/letshelp_certbot
     tests/lock_test.py
 
-[testenv:py26]
-commands =
-    {[base]install_and_test} {[base]py26_packages}
-    python tests/lock_test.py
-deps =
-    setuptools==36.8.0
-    wheel==0.29.0
-passenv = TRAVIS
-
 [testenv]
 commands =
-    {[testenv:py26]commands}
-    {[base]install_and_test} {[base]non_py26_packages}
+    {[base]install_and_test} {[base]all_packages}
+    python tests/lock_test.py
 setenv =
     PYTHONPATH = {toxinidir}
     PYTHONHASHSEED = 0
 passenv =
-    {[testenv:py26]passenv}
-
-[testenv:py33]
-commands =
-    {[testenv]commands}
-deps =
-    wheel==0.29.0
-passenv =
-    {[testenv]passenv}
+    TRAVIS
 
 [testenv:py27-oldest]
 commands =
@@ -104,7 +84,6 @@ passenv =
     {[testenv]passenv}
 
 [testenv:lint]
-# recent versions of pylint do not support Python 2.6 (#97, #187)
 basepython = python2.7
 # separating into multiple invocations disables cross package
 # duplicate code checking; if one of the commands fails, others will