diff -ru ipaddr-2.1.11/ipaddr.py ipaddr-2.1.11-modified/ipaddr.py
 --- ipaddr-2.1.11/ipaddr.py	2014-01-31 13:22:32.000000000 -0800
 +++ ipaddr-2.1.11-modified/ipaddr.py	2017-05-16 16:22:19.672536346 -0700
 @@ -25,6 +25,11 @@
  __version__ = '2.1.11'
  
  import struct
 +import sys
 +
 +if sys.version_info > (3,):
 +    long = int
 +    xrange = range
  
  IPV4LENGTH = 32
  IPV6LENGTH = 128
 @@ -1447,7 +1452,7 @@
  
          try:
              # Now, parse the hextets into a 128-bit integer.
 -            ip_int = 0L
 +            ip_int = long(0)
              for i in xrange(parts_hi):
                  ip_int <<= 16
                  ip_int |= self._parse_hextet(parts[i])
 diff -ru ipaddr-2.1.11/ipaddr_test.py ipaddr-2.1.11-modified/ipaddr_test.py
 --- ipaddr-2.1.11/ipaddr_test.py	2014-01-31 13:02:28.000000000 -0800
 +++ ipaddr-2.1.11-modified/ipaddr_test.py	2017-05-16 16:29:41.029226835 -0700
 @@ -21,6 +21,11 @@
  import unittest
  import time
  import ipaddr
 +import sys
 +
 +if sys.version_info > (3,):
 +    long = int
 +
  
  # Compatibility function to cast str to bytes objects
  if issubclass(ipaddr.Bytes, str):
 @@ -266,7 +271,7 @@
                           '2001:658:22a:cafe:200::1')
  
      def testGetNetmask(self):
 -        self.assertEqual(int(self.ipv4.netmask), 4294967040L)
 +        self.assertEqual(int(self.ipv4.netmask), 4294967040)
          self.assertEqual(str(self.ipv4.netmask), '255.255.255.0')
          self.assertEqual(str(self.ipv4_hostmask.netmask), '255.0.0.0')
          self.assertEqual(int(self.ipv6.netmask),
 @@ -283,7 +288,7 @@
          self.assertEqual(ipv6_zero_netmask._prefix_from_prefix_string('0'), 0)
  
      def testGetBroadcast(self):
 -        self.assertEqual(int(self.ipv4.broadcast), 16909311L)
 +        self.assertEqual(int(self.ipv4.broadcast), 16909311)
          self.assertEqual(str(self.ipv4.broadcast), '1.2.3.255')
  
          self.assertEqual(int(self.ipv6.broadcast),
 @@ -1100,9 +1105,9 @@
  
      def testNetworkElementCaching(self):
          # V4 - make sure we're empty
 -        self.assertFalse(self.ipv4._cache.has_key('network'))
 -        self.assertFalse(self.ipv4._cache.has_key('broadcast'))
 -        self.assertFalse(self.ipv4._cache.has_key('hostmask'))
 +        self.assertFalse('network' in self.ipv4._cache)
 +        self.assertFalse('broadcast' in self.ipv4._cache)
 +        self.assertFalse('hostmask' in self.ipv4._cache)
  
          # V4 - populate and test
          self.assertEqual(self.ipv4.network, ipaddr.IPv4Address('1.2.3.0'))
 @@ -1110,14 +1115,14 @@
          self.assertEqual(self.ipv4.hostmask, ipaddr.IPv4Address('0.0.0.255'))
  
          # V4 - check we're cached
 -        self.assertTrue(self.ipv4._cache.has_key('network'))
 -        self.assertTrue(self.ipv4._cache.has_key('broadcast'))
 -        self.assertTrue(self.ipv4._cache.has_key('hostmask'))
 +        self.assertTrue('network' in self.ipv4._cache)
 +        self.assertTrue('broadcast' in self.ipv4._cache)
 +        self.assertTrue('hostmask' in self.ipv4._cache)
  
          # V6 - make sure we're empty
 -        self.assertFalse(self.ipv6._cache.has_key('network'))
 -        self.assertFalse(self.ipv6._cache.has_key('broadcast'))
 -        self.assertFalse(self.ipv6._cache.has_key('hostmask'))
 +        self.assertFalse('network' in self.ipv6._cache)
 +        self.assertFalse('broadcast' in self.ipv6._cache)
 +        self.assertFalse('hostmask' in self.ipv6._cache)
  
          # V6 - populate and test
          self.assertEqual(self.ipv6.network,
 @@ -1128,9 +1133,9 @@
                           ipaddr.IPv6Address('::ffff:ffff:ffff:ffff'))
  
          # V6 - check we're cached
 -        self.assertTrue(self.ipv6._cache.has_key('network'))
 -        self.assertTrue(self.ipv6._cache.has_key('broadcast'))
 -        self.assertTrue(self.ipv6._cache.has_key('hostmask'))
 +        self.assertTrue('network' in self.ipv6._cache)
 +        self.assertTrue('broadcast' in self.ipv6._cache)
 +        self.assertTrue('hostmask' in self.ipv6._cache)
  
      def testTeredo(self):
          # stolen from wikipedia