diff --git a/python/google/protobuf/internal/_parameterized.py b/python/google/protobuf/internal/_parameterized.py
index 3002b23..6c5a2ba 100755
--- a/python/google/protobuf/internal/_parameterized.py
+++ b/python/google/protobuf/internal/_parameterized.py
@@ -149,7 +149,10 @@
 import functools
 import re
 import types
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 import uuid
 
 import six
diff --git a/python/google/protobuf/internal/descriptor_database_test.py b/python/google/protobuf/internal/descriptor_database_test.py
index 3241cb7..1baff7d 100644
--- a/python/google/protobuf/internal/descriptor_database_test.py
+++ b/python/google/protobuf/internal/descriptor_database_test.py
@@ -34,7 +34,10 @@
 
 __author__ = 'matthewtoia@google.com (Matt Toia)'
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import descriptor_pb2
 from google.protobuf.internal import factory_test2_pb2
 from google.protobuf import descriptor_database
diff --git a/python/google/protobuf/internal/descriptor_pool_test.py b/python/google/protobuf/internal/descriptor_pool_test.py
index 64b5d17..2a482fb 100644
--- a/python/google/protobuf/internal/descriptor_pool_test.py
+++ b/python/google/protobuf/internal/descriptor_pool_test.py
@@ -35,9 +35,11 @@
 __author__ = 'matthewtoia@google.com (Matt Toia)'
 
 import os
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 
-import unittest
 from google.protobuf import unittest_pb2
 from google.protobuf import descriptor_pb2
 from google.protobuf.internal import api_implementation
diff --git a/python/google/protobuf/internal/descriptor_test.py b/python/google/protobuf/internal/descriptor_test.py
index a40ec0e..34843a6 100755
--- a/python/google/protobuf/internal/descriptor_test.py
+++ b/python/google/protobuf/internal/descriptor_test.py
@@ -36,7 +36,6 @@
 
 import sys
 
-import unittest
 from google.protobuf import unittest_custom_options_pb2
 from google.protobuf import unittest_import_pb2
 from google.protobuf import unittest_pb2
@@ -46,6 +45,11 @@
 from google.protobuf import symbol_database
 from google.protobuf import text_format
 
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
+
 
 TEST_EMPTY_MESSAGE_DESCRIPTOR_ASCII = """
 name: 'TestEmptyMessage'
@@ -455,7 +459,7 @@
     # properties of an immutable abc.Mapping.
     self.assertGreater(len(mapping), 0)  # Sized
     self.assertEqual(len(mapping), len(list(mapping)))  # Iterable
-    if sys.version_info.major >= 3:
+    if sys.version_info >= (3,):
       key, item = next(iter(mapping.items()))
     else:
       key, item = mapping.items()[0]
@@ -464,7 +468,7 @@
     # keys(), iterkeys() &co
     item = (next(iter(mapping.keys())), next(iter(mapping.values())))
     self.assertEqual(item, next(iter(mapping.items())))
-    if sys.version_info.major < 3:
+    if sys.version_info < (3,):
       def CheckItems(seq, iterator):
         self.assertEqual(next(iterator), seq[0])
         self.assertEqual(list(iterator), seq[1:])
diff --git a/python/google/protobuf/internal/generator_test.py b/python/google/protobuf/internal/generator_test.py
index f6135fb..bdd7382 100755
--- a/python/google/protobuf/internal/generator_test.py
+++ b/python/google/protobuf/internal/generator_test.py
@@ -41,7 +41,10 @@
 
 __author__ = 'robinson@google.com (Will Robinson)'
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf.internal import test_bad_identifiers_pb2
 from google.protobuf import unittest_custom_options_pb2
 from google.protobuf import unittest_import_pb2
@@ -153,7 +156,7 @@
     # extension and for its value to be set to -789.
 
   def testNestedTypes(self):
-    self.assertEquals(
+    self.assertEqual(
         set(unittest_pb2.TestAllTypes.DESCRIPTOR.nested_types),
         set([
             unittest_pb2.TestAllTypes.NestedMessage.DESCRIPTOR,
diff --git a/python/google/protobuf/internal/message_factory_test.py b/python/google/protobuf/internal/message_factory_test.py
index 27a3f08..0d880a7 100644
--- a/python/google/protobuf/internal/message_factory_test.py
+++ b/python/google/protobuf/internal/message_factory_test.py
@@ -34,7 +34,10 @@
 
 __author__ = 'matthewtoia@google.com (Matt Toia)'
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import descriptor_pb2
 from google.protobuf.internal import factory_test1_pb2
 from google.protobuf.internal import factory_test2_pb2
diff --git a/python/google/protobuf/internal/message_test.py b/python/google/protobuf/internal/message_test.py
index 66356c9..cf3fcfe 100755
--- a/python/google/protobuf/internal/message_test.py
+++ b/python/google/protobuf/internal/message_test.py
@@ -54,7 +54,10 @@
 if six.PY3:
   long = int
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf.internal import _parameterized
 from google.protobuf import map_unittest_pb2
 from google.protobuf import unittest_pb2
@@ -324,7 +327,7 @@
   def testHighPrecisionFloatPrinting(self, message_module):
     message = message_module.TestAllTypes()
     message.optional_double = 0.12345678912345678
-    if sys.version_info.major >= 3:
+    if sys.version_info >= (3,):
       self.assertEqual(str(message), 'optional_double: 0.12345678912345678\n')
     else:
       self.assertEqual(str(message), 'optional_double: 0.123456789123\n')
@@ -443,7 +446,7 @@
     message.repeated_nested_message.sort(key=get_bb, reverse=True)
     self.assertEqual([k.bb for k in message.repeated_nested_message],
                      [6, 5, 4, 3, 2, 1])
-    if sys.version_info.major >= 3: return  # No cmp sorting in PY3.
+    if sys.version_info >= (3,): return  # No cmp sorting in PY3.
     message.repeated_nested_message.sort(sort_function=cmp_bb)
     self.assertEqual([k.bb for k in message.repeated_nested_message],
                      [1, 2, 3, 4, 5, 6])
@@ -462,7 +465,7 @@
     self.assertEqual(list(message.repeated_int32), [-1, -2, -3])
     message.repeated_int32.sort(key=abs, reverse=True)
     self.assertEqual(list(message.repeated_int32), [-3, -2, -1])
-    if sys.version_info.major < 3:  # No cmp sorting in PY3.
+    if sys.version_info < (3,):  # No cmp sorting in PY3.
       abs_cmp = lambda a, b: cmp(abs(a), abs(b))
       message.repeated_int32.sort(sort_function=abs_cmp)
       self.assertEqual(list(message.repeated_int32), [-1, -2, -3])
@@ -476,7 +479,7 @@
     self.assertEqual(list(message.repeated_string), ['c', 'bb', 'aaa'])
     message.repeated_string.sort(key=len, reverse=True)
     self.assertEqual(list(message.repeated_string), ['aaa', 'bb', 'c'])
-    if sys.version_info.major < 3:  # No cmp sorting in PY3.
+    if sys.version_info < (3,):  # No cmp sorting in PY3.
       len_cmp = lambda a, b: cmp(len(a), len(b))
       message.repeated_string.sort(sort_function=len_cmp)
       self.assertEqual(list(message.repeated_string), ['c', 'bb', 'aaa'])
@@ -499,7 +502,7 @@
     m2.repeated_nested_message.add().bb = 2
     m2.repeated_nested_message.add().bb = 3
 
-    if sys.version_info.major >= 3: return  # No cmp() in PY3.
+    if sys.version_info >= (3,): return  # No cmp() in PY3.
 
     # These comparisons should not raise errors.
     _ = m1 < m2
@@ -1248,14 +1251,14 @@
     msg = map_unittest_pb2.TestMap()
 
     self.assertIsNone(msg.map_int32_int32.get(5))
-    self.assertEquals(10, msg.map_int32_int32.get(5, 10))
+    self.assertEqual(10, msg.map_int32_int32.get(5, 10))
     self.assertIsNone(msg.map_int32_int32.get(5))
 
     msg.map_int32_int32[5] = 15
-    self.assertEquals(15, msg.map_int32_int32.get(5))
+    self.assertEqual(15, msg.map_int32_int32.get(5))
 
     self.assertIsNone(msg.map_int32_foreign_message.get(5))
-    self.assertEquals(10, msg.map_int32_foreign_message.get(5, 10))
+    self.assertEqual(10, msg.map_int32_foreign_message.get(5, 10))
 
     submsg = msg.map_int32_foreign_message[5]
     self.assertIs(submsg, msg.map_int32_foreign_message.get(5))
diff --git a/python/google/protobuf/internal/proto_builder_test.py b/python/google/protobuf/internal/proto_builder_test.py
index edaf3fa..1eda10f 100644
--- a/python/google/protobuf/internal/proto_builder_test.py
+++ b/python/google/protobuf/internal/proto_builder_test.py
@@ -32,8 +32,15 @@
 
 """Tests for google.protobuf.proto_builder."""
 
-import collections
-import unittest
+try:
+    from collections import OrderedDict
+except ImportError: 
+    from ordereddict import OrderedDict  #PY26
+
+try:
+  import unittest2 as unittest  #PY26
+except ImportError:
+  import unittest
 
 from google.protobuf import descriptor_pb2
 from google.protobuf import descriptor_pool
@@ -44,7 +51,7 @@
 class ProtoBuilderTest(unittest.TestCase):
 
   def setUp(self):
-    self.ordered_fields = collections.OrderedDict([
+    self.ordered_fields = OrderedDict([
         ('foo', descriptor_pb2.FieldDescriptorProto.TYPE_INT64),
         ('bar', descriptor_pb2.FieldDescriptorProto.TYPE_STRING),
         ])
diff --git a/python/google/protobuf/internal/reflection_test.py b/python/google/protobuf/internal/reflection_test.py
index 9fe3abe..8967dc2 100755
--- a/python/google/protobuf/internal/reflection_test.py
+++ b/python/google/protobuf/internal/reflection_test.py
@@ -39,18 +39,10 @@
 import gc
 import operator
 import struct
-import unittest
 try:
-    from unittest import skipIf
+  import unittest2 as unittest
 except ImportError:
-    def skipIf(predicate, message):
-        def decorator(wrapped):
-            if predicate:
-                def _noop(*args, **kw):
-                    pass
-                return _noop
-            return wrapped
-        return decorator
+  import unittest
 
 import six
 
@@ -1634,7 +1626,7 @@
     self.assertFalse(proto.IsInitialized(errors))
     self.assertEqual(errors, ['a', 'b', 'c'])
 
-  @skipIf(
+  @unittest.skipIf(
       api_implementation.Type() != 'cpp' or api_implementation.Version() != 2,
       'Errors are only available from the most recent C++ implementation.')
   def testFileDescriptorErrors(self):
@@ -2835,7 +2827,7 @@
 
 class ClassAPITest(unittest.TestCase):
 
-  @skipIf(
+  @unittest.skipIf(
       api_implementation.Type() == 'cpp' and api_implementation.Version() == 2,
       'C++ implementation requires a call to MakeDescriptor()')
   def testMakeClassWithNestedDescriptor(self):
diff --git a/python/google/protobuf/internal/service_reflection_test.py b/python/google/protobuf/internal/service_reflection_test.py
index 9967255..d7cd591 100755
--- a/python/google/protobuf/internal/service_reflection_test.py
+++ b/python/google/protobuf/internal/service_reflection_test.py
@@ -34,7 +34,10 @@
 
 __author__ = 'petar@google.com (Petar Petrov)'
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import unittest_pb2
 from google.protobuf import service_reflection
 from google.protobuf import service
diff --git a/python/google/protobuf/internal/symbol_database_test.py b/python/google/protobuf/internal/symbol_database_test.py
index b2489cd..9744226 100644
--- a/python/google/protobuf/internal/symbol_database_test.py
+++ b/python/google/protobuf/internal/symbol_database_test.py
@@ -32,7 +32,10 @@
 
 """Tests for google.protobuf.symbol_database."""
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import unittest_pb2
 from google.protobuf import symbol_database
 
diff --git a/python/google/protobuf/internal/text_encoding_test.py b/python/google/protobuf/internal/text_encoding_test.py
index 9e7b9ce..338a287 100755
--- a/python/google/protobuf/internal/text_encoding_test.py
+++ b/python/google/protobuf/internal/text_encoding_test.py
@@ -32,7 +32,10 @@
 
 """Tests for google.protobuf.text_encoding."""
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import text_encoding
 
 TEST_VALUES = [
diff --git a/python/google/protobuf/internal/text_format_test.py b/python/google/protobuf/internal/text_format_test.py
index 49e6332..67d08df 100755
--- a/python/google/protobuf/internal/text_format_test.py
+++ b/python/google/protobuf/internal/text_format_test.py
@@ -38,7 +38,10 @@
 
 import six
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf.internal import _parameterized
 
 from google.protobuf import map_unittest_pb2
@@ -62,7 +65,7 @@
     self.assertMultiLineEqual(text, ''.join(golden_lines))
 
   def CompareToGoldenText(self, text, golden_text):
-    self.assertMultiLineEqual(text, golden_text)
+    self.assertEqual(text, golden_text)
 
   def RemoveRedundantZeros(self, text):
     # Some platforms print 1e+5 as 1e+005.  This is fine, but we need to remove
@@ -218,13 +221,13 @@
     text_message = text_format.MessageToString(message, float_format='.15g')
     self.CompareToGoldenText(
         self.RemoveRedundantZeros(text_message),
-        'payload {{\n  {}\n  {}\n  {}\n  {}\n}}\n'.format(*formatted_fields))
+        'payload {{\n  {0}\n  {1}\n  {2}\n  {3}\n}}\n'.format(*formatted_fields))
     # as_one_line=True is a separate code branch where float_format is passed.
     text_message = text_format.MessageToString(message, as_one_line=True,
                                                float_format='.15g')
     self.CompareToGoldenText(
         self.RemoveRedundantZeros(text_message),
-        'payload {{ {} {} {} {} }}'.format(*formatted_fields))
+        'payload {{ {0} {1} {2} {3} }}'.format(*formatted_fields))
 
   def testMessageToString(self, message_module):
     message = message_module.ForeignMessage()
@@ -297,7 +300,7 @@
   def testParseSingleWord(self, message_module):
     message = message_module.TestAllTypes()
     text = 'foo'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         (r'1:1 : Message type "\w+.TestAllTypes" has no field named '
          r'"foo".'),
@@ -306,7 +309,7 @@
   def testParseUnknownField(self, message_module):
     message = message_module.TestAllTypes()
     text = 'unknown_field: 8\n'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         (r'1:1 : Message type "\w+.TestAllTypes" has no field named '
          r'"unknown_field".'),
@@ -315,7 +318,7 @@
   def testParseBadEnumValue(self, message_module):
     message = message_module.TestAllTypes()
     text = 'optional_nested_enum: BARR'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         (r'1:23 : Enum type "\w+.TestAllTypes.NestedEnum" '
          r'has no value named BARR.'),
@@ -323,7 +326,7 @@
 
     message = message_module.TestAllTypes()
     text = 'optional_nested_enum: 100'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         (r'1:23 : Enum type "\w+.TestAllTypes.NestedEnum" '
          r'has no value with number 100.'),
@@ -332,7 +335,7 @@
   def testParseBadIntValue(self, message_module):
     message = message_module.TestAllTypes()
     text = 'optional_int32: bork'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         ('1:17 : Couldn\'t parse integer: bork'),
         text_format.Parse, text, message)
@@ -596,12 +599,12 @@
   def testParseBadExtension(self):
     message = unittest_pb2.TestAllExtensions()
     text = '[unknown_extension]: 8\n'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         '1:2 : Extension "unknown_extension" not registered.',
         text_format.Parse, text, message)
     message = unittest_pb2.TestAllTypes()
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         ('1:2 : Message type "protobuf_unittest.TestAllTypes" does not have '
          'extensions.'),
@@ -620,7 +623,7 @@
     message = unittest_pb2.TestAllExtensions()
     text = ('[protobuf_unittest.optional_int32_extension]: 42 '
             '[protobuf_unittest.optional_int32_extension]: 67')
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         ('1:96 : Message type "protobuf_unittest.TestAllExtensions" '
          'should not have multiple '
@@ -631,7 +634,7 @@
     message = unittest_pb2.TestAllTypes()
     text = ('optional_nested_message { bb: 1 } '
             'optional_nested_message { bb: 2 }')
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         ('1:65 : Message type "protobuf_unittest.TestAllTypes.NestedMessage" '
          'should not have multiple "bb" fields.'),
@@ -641,7 +644,7 @@
     message = unittest_pb2.TestAllTypes()
     text = ('optional_int32: 42 '
             'optional_int32: 67')
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError,
         ('1:36 : Message type "protobuf_unittest.TestAllTypes" should not '
          'have multiple "optional_int32" fields.'),
@@ -650,11 +653,11 @@
   def testParseGroupNotClosed(self):
     message = unittest_pb2.TestAllTypes()
     text = 'RepeatedGroup: <'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError, '1:16 : Expected ">".',
         text_format.Parse, text, message)
     text = 'RepeatedGroup: {'
-    self.assertRaisesRegexp(
+    six.assertRaisesRegex(self, 
         text_format.ParseError, '1:16 : Expected "}".',
         text_format.Parse, text, message)
 
diff --git a/python/google/protobuf/internal/unknown_fields_test.py b/python/google/protobuf/internal/unknown_fields_test.py
index 5cd23d7..1b5d7bc 100755
--- a/python/google/protobuf/internal/unknown_fields_test.py
+++ b/python/google/protobuf/internal/unknown_fields_test.py
@@ -35,18 +35,10 @@
 
 __author__ = 'bohdank@google.com (Bohdan Koval)'
 
-import unittest
 try:
-    from unittest import skipIf
+  import unittest2 as unittest
 except ImportError:
-    def skipIf(predicate, message):
-        def decorator(wrapped):
-            if predicate:
-                def _noop(*args, **kw):
-                    pass
-                return _noop
-            return wrapped
-        return decorator
+  import unittest
 
 from google.protobuf import unittest_mset_pb2
 from google.protobuf import unittest_pb2
@@ -129,7 +121,7 @@
     self.assertNotEqual(self.empty_message, message)
 
 
-@skipIf(
+@unittest.skipIf(
     api_implementation.Type() == 'cpp' and api_implementation.Version() == 2,
     'C++ implementation does not expose unknown fields to Python')
 class UnknownFieldsAccessorsTest(unittest.TestCase):
@@ -217,7 +209,7 @@
 
 
 
-@skipIf(
+@unittest.skipIf(
     api_implementation.Type() == 'cpp' and api_implementation.Version() == 2,
     'C++ implementation does not expose unknown fields to Python')
 class UnknownEnumValuesTest(unittest.TestCase):
diff --git a/python/google/protobuf/internal/wire_format_test.py b/python/google/protobuf/internal/wire_format_test.py
index 78dc116..f659d18 100755
--- a/python/google/protobuf/internal/wire_format_test.py
+++ b/python/google/protobuf/internal/wire_format_test.py
@@ -34,7 +34,10 @@
 
 __author__ = 'robinson@google.com (Will Robinson)'
 
-import unittest
+try:
+  import unittest2 as unittest
+except ImportError:
+  import unittest
 from google.protobuf import message
 from google.protobuf.internal import wire_format
 
diff --git a/python/google/protobuf/proto_builder.py b/python/google/protobuf/proto_builder.py
index 7489cf6..700e3c2 100644
--- a/python/google/protobuf/proto_builder.py
+++ b/python/google/protobuf/proto_builder.py
@@ -30,7 +30,10 @@
 
 """Dynamic Protobuf class creator."""
 
-import collections
+try:
+    from collections import OrderedDict
+except ImportError:
+    from ordereddict import OrderedDict  #PY26
 import hashlib
 import os
 
@@ -80,7 +83,7 @@
   # an OrderedDict we keep the order, but otherwise we sort the field to ensure
   # consistent ordering.
   field_items = fields.items()
-  if not isinstance(fields, collections.OrderedDict):
+  if not isinstance(fields, OrderedDict):
     field_items = sorted(field_items)
 
   # Use a consistent file name that is unlikely to conflict with any imported
diff --git a/python/setup.py b/python/setup.py
index bb8a7d0..79e2369 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -158,6 +158,11 @@
     )
     os.environ['PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION'] = 'cpp'
 
+  install_requires = ['six', 'setuptools']
+  if sys.version_info <= (2,7):
+    install_requires.append('ordereddict')
+    install_requires.append('unittest2')
+
   setup(
       name='protobuf',
       version=GetVersion(),
@@ -187,6 +192,6 @@
           'clean': clean,
           'build_py': build_py,
       },
-      install_requires=['setuptools', 'six'],
+      install_requires=install_requires,
       ext_modules=ext_module_list,
   )