diff --git a/mopidy/utils/network.py b/mopidy/utils/network.py
index 6d6c9472..7767377b 100644
--- a/mopidy/utils/network.py
+++ b/mopidy/utils/network.py
@@ -15,7 +15,7 @@ logger = logging.getLogger('mopidy.utils.server')
 class ShouldRetrySocketCall(Exception):
     """Indicate that attempted socket call should be retried"""
 
-def _try_ipv6_socket():
+def try_ipv6_socket():
     """Determine if system really supports IPv6"""
     if not socket.has_ipv6:
         return False
@@ -28,7 +28,7 @@ def _try_ipv6_socket():
     return False
 
 #: Boolean value that indicates if creating an IPv6 socket will succeed.
-has_ipv6 = _try_ipv6_socket()
+has_ipv6 = try_ipv6_socket()
 
 def create_socket():
     """Create a TCP socket with or without IPv6 depending on system support"""
@@ -168,7 +168,8 @@ class Connection(object):
     def enable_recv(self):
         if self.recv_id is None:
             self.recv_id = gobject.io_add_watch(self.sock.fileno(),
-                gobject.IO_IN | gobject.IO_ERR | gobject.IO_HUP, self.recv_callback)
+                gobject.IO_IN | gobject.IO_ERR | gobject.IO_HUP, 
+                self.recv_callback)
 
     def disable_recv(self):
         if self.recv_id is not None:
@@ -254,7 +255,7 @@ class LineProtocol(ThreadingActor):
 
         Should be implemented by subclasses.
         """
-        raise NotImplemented
+        raise NotImplementedError
 
     def on_receive(self, message):
         """Handle messages with new data from server."""
@@ -299,8 +300,8 @@ class LineProtocol(ThreadingActor):
 
         Can be overridden by subclasses to change logging behaviour.
         """
-        logger.debug(u'Request from %s to %s: %s', self.connection, self.actor_urn,
-            indent(request))
+        logger.debug(u'Request from %s to %s: %s', self.connection,
+            self.actor_urn, indent(request))
 
     def log_response(self, response):
         """
diff --git a/requirements/tests.txt b/requirements/tests.txt
index f8cf2eb3..0bc8380f 100644
--- a/requirements/tests.txt
+++ b/requirements/tests.txt
@@ -1,4 +1,4 @@
 coverage
-mock
+mock >= 0.7
 nose
 tox
diff --git a/tests/utils/network_test.py b/tests/utils/network_test.py
index 6fee59d1..e7767689 100644
--- a/tests/utils/network_test.py
+++ b/tests/utils/network_test.py
@@ -24,19 +24,19 @@ class FormatHostnameTest(unittest.TestCase):
 class TryIPv6SocketTest(unittest.TestCase):
     @patch('socket.has_ipv6', False)
     def test_system_that_claims_no_ipv6_support(self):
-        self.assertFalse(network._try_ipv6_socket())
+        self.assertFalse(network.try_ipv6_socket())
 
     @patch('socket.has_ipv6', True)
     @patch('socket.socket')
     def test_system_with_broken_ipv6(self, socket_mock):
         socket_mock.side_effect = IOError()
-        self.assertFalse(network._try_ipv6_socket())
+        self.assertFalse(network.try_ipv6_socket())
 
     @patch('socket.has_ipv6', True)
     @patch('socket.socket')
     def test_with_working_ipv6(self, socket_mock):
         socket_mock.return_value = Mock()
-        self.assertTrue(network._try_ipv6_socket())
+        self.assertTrue(network.try_ipv6_socket())
 
 
 class CreateSocketTest(unittest.TestCase):
@@ -84,7 +84,8 @@ class ServerTest(unittest.TestCase):
         sock = server.create_server_socket.return_value
         fileno = sock.fileno.return_value
 
-        server.create_server_socket.assert_called_once_with(self.host, self.port)
+        server.create_server_socket.assert_called_once_with(
+            self.host, self.port)
         server.register_server_socket.assert_called_once_with(fileno)
 
     @patch.object(network, 'create_socket', spec=socket.SocketType)
@@ -151,7 +152,8 @@ class ServerTest(unittest.TestCase):
 
         server.accept_connection.assert_called_once_with()
         server.maximum_connections_exceeded.assert_called_once_with()
-        server.reject_connection.assert_called_once_with(sentinel.sock, self.addr)
+        server.reject_connection.assert_called_once_with(
+            sentinel.sock, self.addr)
         self.assertEquals(0, server.init_connection.call_count)
 
     def test_accept_connection(self):
@@ -159,17 +161,20 @@ class ServerTest(unittest.TestCase):
         sock = server.create_server_socket.return_value
         sock.accept.return_value = (sentinel.sock, self.addr)
 
-        self.assertEquals((sentinel.sock, self.addr), server.accept_connection())
+        self.assertEquals((sentinel.sock, self.addr),
+            server.accept_connection())
 
     def test_accept_connection_recoverable_error(self):
         server = self.create_server()
         sock = server.create_server_socket.return_value
 
         sock.accept.side_effect = socket.error(errno.EAGAIN, '')
-        self.assertRaises(network.ShouldRetrySocketCall, server.accept_connection)
+        self.assertRaises(network.ShouldRetrySocketCall,
+            server.accept_connection)
 
         sock.accept.side_effect = socket.error(errno.EINTR, '')
-        self.assertRaises(network.ShouldRetrySocketCall, server.accept_connection)
+        self.assertRaises(network.ShouldRetrySocketCall,
+            server.accept_connection)
 
     def test_accept_connection_recoverable_error(self):
         server = self.create_server()
@@ -207,4 +212,6 @@ class ServerTest(unittest.TestCase):
         server = self.create_server()
         server.init_connection(sentinel.sock, self.addr)
 
-        network.Connection.assert_called_once_with(server.protocol, sentinel.sock, self.addr, server.timeout)
+        network.Connection.assert_called_once_with(server.protocol,
+            sentinel.sock, self.addr, server.timeout)
+