diff --git a/letsencrypt/client/le_util.py b/letsencrypt/client/le_util.py
index 3257d5a18..c4a0170e0 100644
--- a/letsencrypt/client/le_util.py
+++ b/letsencrypt/client/le_util.py
@@ -7,6 +7,7 @@ import stat
 
 from letsencrypt.client import errors
 
+
 Key = collections.namedtuple("Key", "file pem")
 
 
diff --git a/letsencrypt/client/standalone_authenticator.py b/letsencrypt/client/standalone_authenticator.py
index 70974180c..9eb6bc392 100644
--- a/letsencrypt/client/standalone_authenticator.py
+++ b/letsencrypt/client/standalone_authenticator.py
@@ -1,11 +1,11 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-"""An authenticator that doesn't rely on any existing server program,
-but instead creates its own ephemeral TCP listener on the specified port
-in order to respond to incoming DVSNI challenges from the certificate
-authority."""
+"""An authenticator that doesn't rely on any existing server program.
 
+This authenticator creates its own ephemeral TCP listener on the specified
+port in order to respond to incoming DVSNI challenges from the certificate
+authority."""
 from letsencrypt.client.challenge_util import DvsniChall
 from letsencrypt.client.challenge_util import dvsni_gen_cert
 from letsencrypt.client import CONFIG
@@ -24,9 +24,11 @@ import zope.interface
 
 class StandaloneAuthenticator(object):
     # pylint: disable=too-many-instance-attributes
-    """The StandaloneAuthenticator class itself, which can be invoked
-    by the Let's Encrypt client according to the IAuthenticator API
-    interface."""
+    """The StandaloneAuthenticator class itself.
+
+    This authenticator can be invoked by the Let's Encrypt client
+    according to the IAuthenticator API interface.  It creates a local
+    TCP listener on a specified port and satisfies DVSNI challenges."""
     zope.interface.implements(interfaces.IAuthenticator)
 
     def __init__(self):
@@ -40,9 +42,10 @@ class StandaloneAuthenticator(object):
         self.ssl_conn = None
 
     def client_signal_handler(self, sig, unused_frame):
-        """Signal handler for the parent process (to receive inter-process
-        communication from the child process in the form of Unix
-        signals."""
+        """Signal handler for the parent process.
+
+        This handler receives inter-process communication from the
+        child process in the form of Unix signals."""
         # signal handler for use in parent process
         # subprocess → client READY   : SIGIO
         # subprocess → client INUSE   : SIGUSR1
@@ -58,9 +61,10 @@ class StandaloneAuthenticator(object):
             assert False
 
     def subproc_signal_handler(self, sig, unused_frame):
-        """Signal handler for the child process (to receive inter-process
-        communication from the parent process in the form of Unix
-        signals."""
+        """Signal handler for the child process.
+
+        This handler receives inter-process communication from the parent
+        process in the form of Unix signals."""
         # signal handler for use in subprocess
         # client → subprocess CLEANUP : SIGINT
         if sig == signal.SIGINT:
@@ -87,9 +91,11 @@ class StandaloneAuthenticator(object):
             sys.exit(0)
 
     def sni_callback(self, connection):
-        """Used internally to set a new OpenSSL context object for this
-        connection when an incoming connection provides an SNI name (in
-        order to serve the appropriate certificate, if any)."""
+        """Used internally to respond to incoming SNI names.
+
+        This method will set a new OpenSSL context object for this
+        connection when an incoming connection provides an SNI name
+        (in order to serve the appropriate certificate, if any)."""
 
         sni_name = connection.get_servername()
         if sni_name in self.tasks:
@@ -107,9 +113,14 @@ class StandaloneAuthenticator(object):
         connection.set_context(new_ctx)
 
     def do_parent_process(self, port, delay_amount=5):
-        """Perform the parent process side of the TCP listener task.  This
-        should only be called by start_listener().  We will wait up to
-        delay_amount seconds to hear from the child process via a signal."""
+        """Perform the parent process side of the TCP listener task.
+
+        This should only be called by start_listener().  We will wait
+        up to delay_amount seconds to hear from the child process via
+        a signal.
+
+        :returns: True or False according to whether we were notified
+        that the child process succeeded or failed in binding the port."""
 
         signal.signal(signal.SIGIO, self.client_signal_handler)
         signal.signal(signal.SIGUSR1, self.client_signal_handler)
@@ -139,8 +150,13 @@ class StandaloneAuthenticator(object):
         return False
 
     def do_child_process(self, port, key):
-        """Perform the child process side of the TCP listener task.  This
-        should only be called by start_listener()."""
+        """Perform the child process side of the TCP listener task.
+
+        This should only be called by start_listener().
+
+        Normally does not return; instead, the child process exits from
+        within this function or from within the child process signal
+        handler."""
         signal.signal(signal.SIGINT, self.subproc_signal_handler)
         self.sock = socket.socket()
         try:
diff --git a/letsencrypt/client/tests/standalone_authenticator_test.py b/letsencrypt/client/tests/standalone_authenticator_test.py
index 911de737a..75a5d22f4 100644
--- a/letsencrypt/client/tests/standalone_authenticator_test.py
+++ b/letsencrypt/client/tests/standalone_authenticator_test.py
@@ -1,7 +1,6 @@
 #!/usr/bin/env python
 
 """Tests for standalone_authenticator.py."""
-
 import mock
 import unittest
 
@@ -44,7 +43,6 @@ class CallableExhausted(Exception):
     # pylint: disable=too-few-public-methods
     """Exception raised when a method is called more than the
     specified number of times."""
-    pass
 
 
 class ChallPrefTest(unittest.TestCase):
@@ -108,7 +106,7 @@ class ClientSignalHandlerTest(unittest.TestCase):
         self.authenticator.child_pid = 12345
 
     def test_client_signal_handler(self):
-        self.assertEqual(self.authenticator.subproc_state, None)
+        self.assertTrue(self.authenticator.subproc_state is None)
         self.authenticator.client_signal_handler(signal.SIGIO, None)
         self.assertEqual(self.authenticator.subproc_state, "ready")
 
diff --git a/setup.py b/setup.py
index c4b44b2bd..1a3a6ddd3 100755
--- a/setup.py
+++ b/setup.py
@@ -26,10 +26,10 @@ install_requires = [
     'jsonschema',
     'mock',
     'pycrypto',
+    'PyOpenSSL',
     'python-augeas',
     'python2-pythondialog',
     'requests',
-    'PyOpenSSL',
     'zope.component',
     'zope.interface',
     # order of items in install_requires DOES matter and M2Crypto has