diff --git a/src/python/grpcio/grpc/_adapter/_types.py b/src/python/grpcio/grpc/_adapter/_types.py
index 3d5ab33d0084aef6d457dd63f4e153125fcc544d..cd273646af3108286406ddfabc214af9b020e3bf 100644
--- a/src/python/grpcio/grpc/_adapter/_types.py
+++ b/src/python/grpcio/grpc/_adapter/_types.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@ import abc
 import collections
 import enum
 
+import six
+
 from grpc._cython import cygrpc
 
 
@@ -247,8 +249,7 @@ class Event(collections.namedtuple(
   """
 
 
-class CompletionQueue:
-  __metaclass__ = abc.ABCMeta
+class CompletionQueue(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def __init__(self):
@@ -285,8 +286,7 @@ class CompletionQueue:
     return None
 
 
-class Call:
-  __metaclass__ = abc.ABCMeta
+class Call(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def start_batch(self, ops, tag):
@@ -334,8 +334,7 @@ class Call:
     return None
 
 
-class Channel:
-  __metaclass__ = abc.ABCMeta
+class Channel(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def __init__(self, target, args, credentials=None):
@@ -399,8 +398,7 @@ class Channel:
     return None
 
 
-class Server:
-  __metaclass__ = abc.ABCMeta
+class Server(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def __init__(self, completion_queue, args):
diff --git a/src/python/grpcio/grpc/_links/invocation.py b/src/python/grpcio/grpc/_links/invocation.py
index 5ca0a0ee606810dd3ec3070e323a989f61ff022b..672e3e4cc86f417e2bd245440400ddce65acff0b 100644
--- a/src/python/grpcio/grpc/_links/invocation.py
+++ b/src/python/grpcio/grpc/_links/invocation.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -35,6 +35,8 @@ import logging
 import threading
 import time
 
+import six
+
 from grpc._adapter import _intermediary_low
 from grpc._links import _constants
 from grpc.beta import interfaces as beta_interfaces
@@ -372,12 +374,11 @@ class _Kernel(object):
     pool.shutdown(wait=True)
 
 
-class InvocationLink(links.Link, activated.Activated):
+class InvocationLink(six.with_metaclass(abc.ABCMeta, links.Link, activated.Activated)):
   """A links.Link for use on the invocation-side of a gRPC connection.
 
   Implementations of this interface are only valid for use when activated.
   """
-  __metaclass__ = abc.ABCMeta
 
 
 class _InvocationLink(InvocationLink):
diff --git a/src/python/grpcio/grpc/beta/interfaces.py b/src/python/grpcio/grpc/beta/interfaces.py
index 0663119163f2eadea3e2d34319da0ae2ce3b1ed5..e29a5b33792af32d3960d0f5fcc035f42da1e529 100644
--- a/src/python/grpcio/grpc/beta/interfaces.py
+++ b/src/python/grpcio/grpc/beta/interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,8 @@
 import abc
 import enum
 
+import six
+
 from grpc._adapter import _types
 
 
@@ -105,19 +107,17 @@ def grpc_call_options(disable_compression=False, credentials=None):
   return GRPCCallOptions(disable_compression, None, credentials)
 
 
-class GRPCAuthMetadataContext(object):
+class GRPCAuthMetadataContext(six.with_metaclass(abc.ABCMeta)):
   """Provides information to call credentials metadata plugins.
 
   Attributes:
     service_url: A string URL of the service being called into.
     method_name: A string of the fully qualified method name being called.
   """
-  __metaclass__ = abc.ABCMeta
 
 
-class GRPCAuthMetadataPluginCallback(object):
+class GRPCAuthMetadataPluginCallback(six.with_metaclass(abc.ABCMeta)):
   """Callback object received by a metadata plugin."""
-  __metaclass__ = abc.ABCMeta
 
   def __call__(self, metadata, error):
     """Inform the gRPC runtime of the metadata to construct a CallCredentials.
@@ -130,10 +130,9 @@ class GRPCAuthMetadataPluginCallback(object):
     raise NotImplementedError()
 
 
-class GRPCAuthMetadataPlugin(object):
+class GRPCAuthMetadataPlugin(six.with_metaclass(abc.ABCMeta)):
   """
   """
-  __metaclass__ = abc.ABCMeta
 
   def __call__(self, context, callback):
     """Invoke the plugin.
@@ -149,9 +148,8 @@ class GRPCAuthMetadataPlugin(object):
     raise NotImplementedError()
 
 
-class GRPCServicerContext(object):
+class GRPCServicerContext(six.with_metaclass(abc.ABCMeta)):
   """Exposes gRPC-specific options and behaviors to code servicing RPCs."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def peer(self):
@@ -168,9 +166,8 @@ class GRPCServicerContext(object):
     raise NotImplementedError()
 
 
-class GRPCInvocationContext(object):
+class GRPCInvocationContext(six.with_metaclass(abc.ABCMeta)):
   """Exposes gRPC-specific options and behaviors to code invoking RPCs."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def disable_next_request_compression(self):
@@ -178,9 +175,8 @@ class GRPCInvocationContext(object):
     raise NotImplementedError()
 
 
-class Server(object):
+class Server(six.with_metaclass(abc.ABCMeta)):
   """Services RPCs."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def add_insecure_port(self, address):
diff --git a/src/python/grpcio/grpc/framework/alpha/_face_utilities.py b/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
index fb0cfe426d0614f27f381e5dd2be0fd764e33647..c97307df161c01f0c96acee091ee1e87703b9ed9 100644
--- a/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
+++ b/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -30,6 +30,8 @@
 import abc
 import collections
 
+import six
+
 # face_interfaces is referenced from specification in this module.
 from grpc.framework.common import cardinality
 from grpc.framework.face import interfaces as face_interfaces  # pylint: disable=unused-import
@@ -45,7 +47,7 @@ def _qualified_name(service_name, method_name):
 # TODO(nathaniel): This structure is getting bloated; it could be shrunk if
 # implementations._Stub used a generic rather than a dynamic underlying
 # face-layer stub.
-class InvocationBreakdown(object):
+class InvocationBreakdown(six.with_metaclass(abc.ABCMeta)):
   """An intermediate representation of invocation-side views of RPC methods.
 
   Attributes:
@@ -61,7 +63,6 @@ class InvocationBreakdown(object):
       to callable behavior to be used deserializing response values for the
       RPC.
   """
-  __metaclass__ = abc.ABCMeta
 
 
 class _EasyInvocationBreakdown(
@@ -73,7 +74,7 @@ class _EasyInvocationBreakdown(
   pass
 
 
-class ServiceBreakdown(object):
+class ServiceBreakdown(six.with_metaclass(abc.ABCMeta)):
   """An intermediate representation of service-side views of RPC methods.
 
   Attributes:
@@ -84,7 +85,6 @@ class ServiceBreakdown(object):
     response_serializers: A dictionary from service-qualified RPC method name
       to callable behavior to be used serializing response values for the RPC.
   """
-  __metaclass__ = abc.ABCMeta
 
 
 class _EasyServiceBreakdown(
diff --git a/src/python/grpcio/grpc/framework/alpha/exceptions.py b/src/python/grpcio/grpc/framework/alpha/exceptions.py
index 5234d3b91cebbffc07efa29c8738614ec2196460..8ec260488e8cfa8b12af09852899e05ea9e4f19f 100644
--- a/src/python/grpcio/grpc/framework/alpha/exceptions.py
+++ b/src/python/grpcio/grpc/framework/alpha/exceptions.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,13 +31,12 @@
 
 Only GRPC should instantiate and raise these exceptions.
 """
-
 import abc
 
+import six
 
-class RpcError(Exception):
+class RpcError(six.with_metaclass(abc.ABCMeta, Exception)):
   """Common super type for all exceptions raised by GRPC."""
-  __metaclass__ = abc.ABCMeta
 
 
 class CancellationError(RpcError):
diff --git a/src/python/grpcio/grpc/framework/alpha/interfaces.py b/src/python/grpcio/grpc/framework/alpha/interfaces.py
index 8380567c97205dfa35676a314e92578e0f3631f4..57e4b5e31524e0bfb7f3d94eab6e2ed5bb002885 100644
--- a/src/python/grpcio/grpc/framework/alpha/interfaces.py
+++ b/src/python/grpcio/grpc/framework/alpha/interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,8 @@
 import abc
 import enum
 
+import six
+
 # exceptions is referenced from specification in this module.
 from grpc.framework.alpha import exceptions  # pylint: disable=unused-import
 from grpc.framework.foundation import activated
@@ -59,9 +61,8 @@ class Abortion(enum.Enum):
   SERVICER_FAILURE = 'servicer failure'
 
 
-class CancellableIterator(object):
+class CancellableIterator(six.with_metaclass(abc.ABCMeta)):
   """Implements the Iterator protocol and affords a cancel method."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __iter__(self):
@@ -79,9 +80,8 @@ class CancellableIterator(object):
     raise NotImplementedError()
 
 
-class RpcContext(object):
+class RpcContext(six.with_metaclass(abc.ABCMeta)):
   """Provides RPC-related information and action."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def is_active(self):
@@ -108,7 +108,7 @@ class RpcContext(object):
     raise NotImplementedError()
 
 
-class UnaryUnarySyncAsync(object):
+class UnaryUnarySyncAsync(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-unary RPC synchronously or asynchronously.
   Values implementing this interface are directly callable and present an
   "async" method. Both calls take a request value and a numeric timeout.
@@ -117,7 +117,6 @@ class UnaryUnarySyncAsync(object):
   of a value of this type invokes its associated RPC and immediately returns a
   future.Future bound to the asynchronous execution of the RPC.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request, timeout):
@@ -147,7 +146,7 @@ class UnaryUnarySyncAsync(object):
     raise NotImplementedError()
 
 
-class StreamUnarySyncAsync(object):
+class StreamUnarySyncAsync(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-unary RPC synchronously or asynchronously.
   Values implementing this interface are directly callable and present an
   "async" method. Both calls take an iterator of request values and a numeric
@@ -156,7 +155,6 @@ class StreamUnarySyncAsync(object):
   of a value of this type invokes its associated RPC and immediately returns a
   future.Future bound to the asynchronous execution of the RPC.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request_iterator, timeout):
@@ -191,9 +189,8 @@ class StreamUnarySyncAsync(object):
     raise NotImplementedError()
 
 
-class RpcMethodDescription(object):
+class RpcMethodDescription(six.with_metaclass(abc.ABCMeta)):
   """A type for the common aspects of RPC method descriptions."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def cardinality(self):
@@ -207,9 +204,8 @@ class RpcMethodDescription(object):
     raise NotImplementedError()
 
 
-class RpcMethodInvocationDescription(RpcMethodDescription):
+class RpcMethodInvocationDescription(six.with_metaclass(abc.ABCMeta, RpcMethodDescription)):
   """Invocation-side description of an RPC method."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def serialize_request(self, request):
@@ -240,9 +236,8 @@ class RpcMethodInvocationDescription(RpcMethodDescription):
     raise NotImplementedError()
 
 
-class RpcMethodServiceDescription(RpcMethodDescription):
+class RpcMethodServiceDescription(six.with_metaclass(abc.ABCMeta, RpcMethodDescription)):
   """Service-side description of an RPC method."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def deserialize_request(self, serialized_request):
@@ -345,7 +340,7 @@ class RpcMethodServiceDescription(RpcMethodDescription):
     raise NotImplementedError()
 
 
-class Stub(object):
+class Stub(six.with_metaclass(abc.ABCMeta)):
   """A stub with callable RPC method names for attributes.
 
   Instances of this type are context managers and only afford RPC invocation
@@ -369,12 +364,10 @@ class Stub(object):
   exceptions.RpcError, exceptions.CancellationError,
   and exceptions.ExpirationError.
   """
-  __metaclass__ = abc.ABCMeta
 
 
-class Server(activated.Activated):
+class Server(six.with_metaclass(abc.ABCMeta, activated.Activated)):
   """A GRPC Server."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def port(self):
diff --git a/src/python/grpcio/grpc/framework/base/_ingestion.py b/src/python/grpcio/grpc/framework/base/_ingestion.py
index 06d5b92f0b3fbcbd3ee4afd810a58afad22d4595..090cb158c94cec7e018ce9c62fb66dcd3a023768 100644
--- a/src/python/grpcio/grpc/framework/base/_ingestion.py
+++ b/src/python/grpcio/grpc/framework/base/_ingestion.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,8 @@
 import abc
 import collections
 
+import six
+
 from grpc.framework.base import _constants
 from grpc.framework.base import _interfaces
 from grpc.framework.base import exceptions
@@ -72,9 +74,8 @@ class _EmptyConsumer(stream.Consumer):
     """See stream.Consumer.consume_and_terminate for specification."""
 
 
-class _ConsumerCreator(object):
+class _ConsumerCreator(six.with_metaclass(abc.ABCMeta)):
   """Common specification of different consumer-creating behavior."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def create_consumer(self, requirement):
diff --git a/src/python/grpcio/grpc/framework/base/_interfaces.py b/src/python/grpcio/grpc/framework/base/_interfaces.py
index d88cf76590e3039a4b22ff7efb3f0a5674b50a35..c0cc866cad47e65d9ac99c0c594555fd73280774 100644
--- a/src/python/grpcio/grpc/framework/base/_interfaces.py
+++ b/src/python/grpcio/grpc/framework/base/_interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,14 +31,15 @@
 
 import abc
 
+import six
+
 # interfaces is referenced from specification in this module.
 from grpc.framework.base import interfaces  # pylint: disable=unused-import
 from grpc.framework.foundation import stream
 
 
-class TerminationManager(object):
+class TerminationManager(six.with_metaclass(abc.ABCMeta)):
   """An object responsible for handling the termination of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_expiration_manager(self, expiration_manager):
@@ -91,9 +92,8 @@ class TerminationManager(object):
     raise NotImplementedError()
 
 
-class TransmissionManager(object):
+class TransmissionManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for transmitting to the other end of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def inmit(self, emission, complete):
@@ -117,9 +117,8 @@ class TransmissionManager(object):
     raise NotImplementedError()
 
 
-class EmissionManager(stream.Consumer):
+class EmissionManager(six.with_metaclass(abc.ABCMeta, stream.Consumer)):
   """A manager of values emitted by customer code."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_ingestion_manager_and_expiration_manager(
@@ -166,9 +165,8 @@ class EmissionManager(stream.Consumer):
     raise NotImplementedError()
 
 
-class IngestionManager(stream.Consumer):
+class IngestionManager(six.with_metaclass(abc.ABCMeta, stream.Consumer)):
   """A manager responsible for executing customer code."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_expiration_manager(self, expiration_manager):
@@ -214,9 +212,8 @@ class IngestionManager(stream.Consumer):
     raise NotImplementedError()
 
 
-class ExpirationManager(object):
+class ExpirationManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for aborting the operation if it runs out of time."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def change_timeout(self, timeout):
@@ -246,9 +243,8 @@ class ExpirationManager(object):
     raise NotImplementedError()
 
 
-class ReceptionManager(object):
+class ReceptionManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for receiving tickets from the other end."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def receive_ticket(self, ticket):
@@ -261,9 +257,8 @@ class ReceptionManager(object):
     raise NotImplementedError()
 
 
-class CancellationManager(object):
+class CancellationManager(six.with_metaclass(abc.ABCMeta)):
   """A manager of operation cancellation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def cancel(self):
diff --git a/src/python/grpcio/grpc/framework/base/_reception.py b/src/python/grpcio/grpc/framework/base/_reception.py
index dd428964f1558e1db8e443cc7ab371946c4c718d..2bee3947f0af0e9b802c10eff7840831ca1412cc 100644
--- a/src/python/grpcio/grpc/framework/base/_reception.py
+++ b/src/python/grpcio/grpc/framework/base/_reception.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 from grpc.framework.base import interfaces
 from grpc.framework.base import _interfaces
 
@@ -40,9 +42,8 @@ _INITIAL_FRONT_TO_BACK_TICKET_KINDS = (
 )
 
 
-class _Receiver(object):
+class _Receiver(six.with_metaclass(abc.ABCMeta)):
   """Common specification of different ticket-handling behavior."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def abort_if_abortive(self, ticket):
diff --git a/src/python/grpcio/grpc/framework/base/_transmission.py b/src/python/grpcio/grpc/framework/base/_transmission.py
index 684512923443a8ca4e85ec5989762f77180cdd04..398faaf3146a6e170f3cd12b857257b70b7606c1 100644
--- a/src/python/grpcio/grpc/framework/base/_transmission.py
+++ b/src/python/grpcio/grpc/framework/base/_transmission.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 from grpc.framework.base import _constants
 from grpc.framework.base import _interfaces
 from grpc.framework.base import interfaces
@@ -77,9 +79,8 @@ _ABORTION_OUTCOME_TO_BACK_TO_FRONT_TICKET_KIND = {
 }
 
 
-class _Ticketizer(object):
+class _Ticketizer(six.with_metaclass(abc.ABCMeta)):
   """Common specification of different ticket-creating behavior."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def ticketize(self, operation_id, sequence_number, payload, complete):
@@ -187,9 +188,8 @@ class _BackTicketizer(_Ticketizer):
           operation_id, sequence_number, kind, None)
 
 
-class TransmissionManager(_interfaces.TransmissionManager):
+class TransmissionManager(six.with_metaclass(abc.ABCMeta, _interfaces.TransmissionManager)):
   """A _interfaces.TransmissionManager on which other managers may be set."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_ingestion_and_expiration_managers(
diff --git a/src/python/grpcio/grpc/framework/base/interfaces.py b/src/python/grpcio/grpc/framework/base/interfaces.py
index e22c10d9750625b9e34590dc6275d5d4ceeee5cd..7c58a23ce05d78583a2115a4b436d6669560d8e3 100644
--- a/src/python/grpcio/grpc/framework/base/interfaces.py
+++ b/src/python/grpcio/grpc/framework/base/interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@ import abc
 import collections
 import enum
 
+import six
+
 # stream is referenced from specification in this module.
 from grpc.framework.foundation import stream  # pylint: disable=unused-import
 
@@ -50,13 +52,12 @@ class Outcome(enum.Enum):
   SERVICED_FAILURE = 'serviced failure'
 
 
-class OperationContext(object):
+class OperationContext(six.with_metaclass(abc.ABCMeta)):
   """Provides operation-related information and action.
 
   Attributes:
     trace_id: A uuid.UUID identifying a particular set of related operations.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def is_active(self):
@@ -93,9 +94,8 @@ class OperationContext(object):
     raise NotImplementedError()
 
 
-class Servicer(object):
+class Servicer(six.with_metaclass(abc.ABCMeta)):
   """Interface for service implementations."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def service(self, name, context, output_consumer):
@@ -120,7 +120,7 @@ class Servicer(object):
     raise NotImplementedError()
 
 
-class Operation(object):
+class Operation(six.with_metaclass(abc.ABCMeta)):
   """Representation of an in-progress operation.
 
   Attributes:
@@ -129,7 +129,6 @@ class Operation(object):
     context: An OperationContext affording information and action about the
       operation.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def cancel(self):
@@ -137,9 +136,8 @@ class Operation(object):
     raise NotImplementedError()
 
 
-class ServicedIngestor(object):
+class ServicedIngestor(six.with_metaclass(abc.ABCMeta)):
   """Responsible for accepting the result of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def consumer(self, operation_context):
@@ -159,7 +157,7 @@ class ServicedIngestor(object):
     raise NotImplementedError()
 
 
-class ServicedSubscription(object):
+class ServicedSubscription(six.with_metaclass(abc.ABCMeta)):
   """A sum type representing a serviced's interest in an operation.
 
   Attributes:
@@ -167,7 +165,6 @@ class ServicedSubscription(object):
     ingestor: A ServicedIngestor. Must be present if kind is Kind.FULL. Must
       be None if kind is Kind.TERMINATION_ONLY or Kind.NONE.
   """
-  __metaclass__ = abc.ABCMeta
 
   @enum.unique
   class Kind(enum.Enum):
@@ -178,9 +175,8 @@ class ServicedSubscription(object):
     NONE = 'none'
 
 
-class End(object):
+class End(six.with_metaclass(abc.ABCMeta)):
   """Common type for entry-point objects on both sides of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def operation_stats(self):
@@ -202,9 +198,8 @@ class End(object):
     raise NotImplementedError()
 
 
-class Front(End):
+class Front(six.with_metaclass(abc.ABCMeta, End)):
   """Clientish objects that afford the invocation of operations."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def operate(
@@ -228,9 +223,8 @@ class Front(End):
     raise NotImplementedError()
 
 
-class Back(End):
+class Back(six.with_metaclass(abc.ABCMeta, End)):
   """Serverish objects that perform the work of operations."""
-  __metaclass__ = abc.ABCMeta
 
 
 class FrontToBackTicket(
@@ -315,9 +309,8 @@ class BackToFrontTicket(
     TRANSMISSION_FAILURE = 'transmission failure'
 
 
-class ForeLink(object):
+class ForeLink(six.with_metaclass(abc.ABCMeta)):
   """Accepts back-to-front tickets and emits front-to-back tickets."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def accept_back_to_front_ticket(self, ticket):
@@ -334,9 +327,8 @@ class ForeLink(object):
     raise NotImplementedError()
 
 
-class RearLink(object):
+class RearLink(six.with_metaclass(abc.ABCMeta)):
   """Accepts front-to-back tickets and emits back-to-front tickets."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def accept_front_to_back_ticket(self, ticket):
@@ -353,11 +345,9 @@ class RearLink(object):
     raise NotImplementedError()
 
 
-class FrontLink(Front, ForeLink):
+class FrontLink(six.with_metaclass(abc.ABCMeta, Front, ForeLink)):
   """Clientish objects that operate by sending and receiving tickets."""
-  __metaclass__ = abc.ABCMeta
 
 
-class BackLink(Back, RearLink):
+class BackLink(six.with_metaclass(abc.ABCMeta, Back, RearLink)):
   """Serverish objects that operate by sending and receiving tickets."""
-  __metaclass__ = abc.ABCMeta
diff --git a/src/python/grpcio/grpc/framework/core/_end.py b/src/python/grpcio/grpc/framework/core/_end.py
index 9c615672aa71ee843f976cce15b97f68012bb6e1..dc2f48589ad5bbe0f6ef0834011f2b1910a6bb33 100644
--- a/src/python/grpcio/grpc/framework/core/_end.py
+++ b/src/python/grpcio/grpc/framework/core/_end.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@ import abc
 import threading
 import uuid
 
+import six
+
 from grpc.framework.core import _operation
 from grpc.framework.core import _utilities
 from grpc.framework.foundation import callable_util
@@ -45,7 +47,7 @@ from grpc.framework.interfaces.links import utilities
 _IDLE_ACTION_EXCEPTION_LOG_MESSAGE = 'Exception calling idle action!'
 
 
-class End(base.End, links.Link):
+class End(six.with_metaclass(abc.ABCMeta, base.End, links.Link)):
   """A bridge between base.End and links.Link.
 
   Implementations of this interface translate arriving tickets into
@@ -53,7 +55,6 @@ class End(base.End, links.Link):
   translate calls from application objects implementing base interfaces
   into tickets sent to a joined link.
   """
-  __metaclass__ = abc.ABCMeta
 
 
 class _Cycle(object):
diff --git a/src/python/grpcio/grpc/framework/core/_ingestion.py b/src/python/grpcio/grpc/framework/core/_ingestion.py
index 4129a8ce43e10ee8d6e4217013371faf34998348..1e1fd73ce437db525b7485c9d6e8bed5d4679e94 100644
--- a/src/python/grpcio/grpc/framework/core/_ingestion.py
+++ b/src/python/grpcio/grpc/framework/core/_ingestion.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@ import abc
 import collections
 import enum
 
+import six
+
 from grpc.framework.core import _constants
 from grpc.framework.core import _interfaces
 from grpc.framework.core import _utilities
@@ -70,9 +72,8 @@ class _SubscriptionCreation(
     ABANDONED = 'abandoned'
 
 
-class _SubscriptionCreator(object):
+class _SubscriptionCreator(six.with_metaclass(abc.ABCMeta)):
   """Common specification of subscription-creating behavior."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def create(self, group, method):
diff --git a/src/python/grpcio/grpc/framework/core/_interfaces.py b/src/python/grpcio/grpc/framework/core/_interfaces.py
index ffa686b2b79b75f79859077dbb29ad59be4d3874..985e5e8550acf69fadd15d638858b0e832487bad 100644
--- a/src/python/grpcio/grpc/framework/core/_interfaces.py
+++ b/src/python/grpcio/grpc/framework/core/_interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,17 +31,18 @@
 
 import abc
 
+import six
+
 from grpc.framework.interfaces.base import base
 
 
-class TerminationManager(object):
+class TerminationManager(six.with_metaclass(abc.ABCMeta)):
   """An object responsible for handling the termination of an operation.
 
   Attributes:
     outcome: None if the operation is active or a base.Outcome value if it has
       terminated.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def add_callback(self, callback):
@@ -105,9 +106,8 @@ class TerminationManager(object):
     raise NotImplementedError()
 
 
-class TransmissionManager(object):
+class TransmissionManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for transmitting to the other end of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def kick_off(
@@ -171,9 +171,8 @@ class TransmissionManager(object):
     raise NotImplementedError()
 
 
-class ExpirationManager(object):
+class ExpirationManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for aborting the operation if it runs out of time."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def change_timeout(self, timeout):
@@ -203,9 +202,8 @@ class ExpirationManager(object):
     raise NotImplementedError()
 
 
-class ProtocolManager(object):
+class ProtocolManager(six.with_metaclass(abc.ABCMeta)):
   """A manager of protocol-specific values passing through an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_protocol_receiver(self, protocol_receiver):
@@ -228,9 +226,8 @@ class ProtocolManager(object):
     raise NotImplementedError()
 
 
-class EmissionManager(base.Operator):
+class EmissionManager(six.with_metaclass(abc.ABCMeta, base.Operator)):
   """A manager of values emitted by customer code."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def advance(
@@ -254,14 +251,13 @@ class EmissionManager(base.Operator):
     raise NotImplementedError()
 
 
-class IngestionManager(object):
+class IngestionManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for executing customer code.
 
   This name of this manager comes from its responsibility to pass successive
   values from the other side of the operation into the code of the local
   customer.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_group_and_method(self, group, method):
@@ -294,9 +290,8 @@ class IngestionManager(object):
     raise NotImplementedError()
 
 
-class ReceptionManager(object):
+class ReceptionManager(six.with_metaclass(abc.ABCMeta)):
   """A manager responsible for receiving tickets from the other end."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def receive_ticket(self, ticket):
@@ -308,7 +303,7 @@ class ReceptionManager(object):
     raise NotImplementedError()
 
 
-class Operation(object):
+class Operation(six.with_metaclass(abc.ABCMeta)):
   """An ongoing operation.
 
   Attributes:
@@ -316,7 +311,6 @@ class Operation(object):
     operator: A base.Operator object for the operation for use by the customer
       of the operation.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def handle_ticket(self, ticket):
diff --git a/src/python/grpcio/grpc/framework/core/_termination.py b/src/python/grpcio/grpc/framework/core/_termination.py
index 364158b2b8764003b89f0d93939d0ce8e8c7793b..e8c4ec60a323059da14797689489ef4ca2b6660f 100644
--- a/src/python/grpcio/grpc/framework/core/_termination.py
+++ b/src/python/grpcio/grpc/framework/core/_termination.py
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 from grpc.framework.core import _constants
 from grpc.framework.core import _interfaces
 from grpc.framework.core import _utilities
@@ -50,9 +52,8 @@ def _service_completion_predicate(
   return transmission_complete and ingestion_complete
 
 
-class TerminationManager(_interfaces.TerminationManager):
+class TerminationManager(six.with_metaclass(abc.ABCMeta, _interfaces.TerminationManager)):
   """A _interfaces.TransmissionManager on which another manager may be set."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_expiration_manager(self, expiration_manager):
diff --git a/src/python/grpcio/grpc/framework/face/exceptions.py b/src/python/grpcio/grpc/framework/face/exceptions.py
index f112df70bc694ba0aed9e6f22067d086366a2d8d..c272ac75ab933375935e122869023791a6809845 100644
--- a/src/python/grpcio/grpc/framework/face/exceptions.py
+++ b/src/python/grpcio/grpc/framework/face/exceptions.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 
 class NoSuchMethodError(Exception):
   """Raised by customer code to indicate an unrecognized RPC method name.
@@ -49,12 +51,11 @@ class NoSuchMethodError(Exception):
     self.name = name
 
 
-class RpcError(Exception):
+class RpcError(six.with_metaclass(abc.ABCMeta, Exception)):
   """Common super type for all exceptions raised by the Face layer.
 
   Only RPC Framework should instantiate and raise these exceptions.
   """
-  __metaclass__ = abc.ABCMeta
 
 
 class CancellationError(RpcError):
diff --git a/src/python/grpcio/grpc/framework/face/interfaces.py b/src/python/grpcio/grpc/framework/face/interfaces.py
index b7cc4c1169ab9e87ca29511105f8a227699c870f..1b9a674be0c6441a5cde4b26dfb24f1c49ddb58f 100644
--- a/src/python/grpcio/grpc/framework/face/interfaces.py
+++ b/src/python/grpcio/grpc/framework/face/interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,8 @@
 import abc
 import enum
 
+import six
+
 # cardinality, style, exceptions, abandonment, future, and stream are
 # referenced from specification in this module.
 from grpc.framework.common import cardinality  # pylint: disable=unused-import
@@ -52,9 +54,8 @@ class Abortion(enum.Enum):
   SERVICER_FAILURE = 'servicer failure'
 
 
-class CancellableIterator(object):
+class CancellableIterator(six.with_metaclass(abc.ABCMeta)):
   """Implements the Iterator protocol and affords a cancel method."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __iter__(self):
@@ -72,9 +73,8 @@ class CancellableIterator(object):
     raise NotImplementedError()
 
 
-class RpcContext(object):
+class RpcContext(six.with_metaclass(abc.ABCMeta)):
   """Provides RPC-related information and action."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def is_active(self):
@@ -103,13 +103,12 @@ class RpcContext(object):
     raise NotImplementedError()
 
 
-class Call(object):
+class Call(six.with_metaclass(abc.ABCMeta)):
   """Invocation-side representation of an RPC.
 
   Attributes:
     context: An RpcContext affording information about the RPC.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def cancel(self):
@@ -117,9 +116,8 @@ class Call(object):
     raise NotImplementedError()
 
 
-class UnaryUnaryMultiCallable(object):
+class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-unary RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request, timeout):
@@ -171,9 +169,8 @@ class UnaryUnaryMultiCallable(object):
     raise NotImplementedError()
 
 
-class UnaryStreamMultiCallable(object):
+class UnaryStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-stream RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request, timeout):
@@ -209,9 +206,8 @@ class UnaryStreamMultiCallable(object):
     raise NotImplementedError()
 
 
-class StreamUnaryMultiCallable(object):
+class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-unary RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request_iterator, timeout):
@@ -264,9 +260,8 @@ class StreamUnaryMultiCallable(object):
     raise NotImplementedError()
 
 
-class StreamStreamMultiCallable(object):
+class StreamStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-stream RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request_iterator, timeout):
@@ -302,7 +297,7 @@ l    Args:
     raise NotImplementedError()
 
 
-class MethodImplementation(object):
+class MethodImplementation(six.with_metaclass(abc.ABCMeta)):
   """A sum type that describes an RPC method implementation.
 
   Attributes:
@@ -347,12 +342,10 @@ class MethodImplementation(object):
       is cardinality.Cardinality.STREAM_STREAM and style is
       style.Service.EVENT.
   """
-  __metaclass__ = abc.ABCMeta
 
 
-class MultiMethodImplementation(object):
+class MultiMethodImplementation(six.with_metaclass(abc.ABCMeta)):
   """A general type able to service many RPC methods."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def service(self, name, response_consumer, context):
@@ -381,9 +374,8 @@ class MultiMethodImplementation(object):
     raise NotImplementedError()
 
 
-class GenericStub(object):
+class GenericStub(six.with_metaclass(abc.ABCMeta)):
   """Affords RPC methods to callers."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def blocking_value_in_value_out(self, name, request, timeout):
@@ -622,7 +614,7 @@ class GenericStub(object):
     raise NotImplementedError()
 
 
-class DynamicStub(object):
+class DynamicStub(six.with_metaclass(abc.ABCMeta)):
   """A stub with RPC-method-bound multi-callable attributes.
 
   Instances of this type responsd to attribute access as follows: if the
@@ -637,4 +629,3 @@ class DynamicStub(object):
   the attribute will be a StreamStreamMultiCallable with which to invoke the
   RPC method.
   """
-  __metaclass__ = abc.ABCMeta
diff --git a/src/python/grpcio/grpc/framework/foundation/activated.py b/src/python/grpcio/grpc/framework/foundation/activated.py
index 426a71c7059eb7c866865c3d898e69eef504c6b6..9b49b6363c10f5dece70b003b3974f32374f6b27 100644
--- a/src/python/grpcio/grpc/framework/foundation/activated.py
+++ b/src/python/grpcio/grpc/framework/foundation/activated.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,14 +31,14 @@
 
 import abc
 
+import six
 
-class Activated(object):
+class Activated(six.with_metaclass(abc.ABCMeta)):
   """Interface for objects that may be started and stopped.
 
   Values implementing this type must also implement the context manager
   protocol.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __enter__(self):
diff --git a/src/python/grpcio/grpc/framework/foundation/callable_util.py b/src/python/grpcio/grpc/framework/foundation/callable_util.py
index 32b0751a01c3fc253ab6c6a9e4f6d9e09dd6cda7..e0a4cab7381fe532e9f1f217661e8489525e4530 100644
--- a/src/python/grpcio/grpc/framework/foundation/callable_util.py
+++ b/src/python/grpcio/grpc/framework/foundation/callable_util.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -35,8 +35,10 @@ import enum
 import functools
 import logging
 
+import six
 
-class Outcome(object):
+
+class Outcome(six.with_metaclass(abc.ABCMeta)):
   """A sum type describing the outcome of some call.
 
   Attributes:
@@ -47,7 +49,6 @@ class Outcome(object):
     exception: The exception raised by the call. Must be present if kind is
       Kind.RAISED.
   """
-  __metaclass__ = abc.ABCMeta
 
   @enum.unique
   class Kind(enum.Enum):
diff --git a/src/python/grpcio/grpc/framework/foundation/future.py b/src/python/grpcio/grpc/framework/foundation/future.py
index bfc16fc1eaa2f679933300512fa143ff8b5210f2..bb8ee3ad87164e77a630308c97819f94cbe7403e 100644
--- a/src/python/grpcio/grpc/framework/foundation/future.py
+++ b/src/python/grpcio/grpc/framework/foundation/future.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -49,6 +49,8 @@ built-in-but-only-in-3.3-and-later TimeoutError.
 
 import abc
 
+import six
+
 
 class TimeoutError(Exception):
   """Indicates that a particular call timed out."""
@@ -58,13 +60,12 @@ class CancelledError(Exception):
   """Indicates that the computation underlying a Future was cancelled."""
 
 
-class Future(object):
+class Future(six.with_metaclass(abc.ABCMeta)):
   """A representation of a computation in another control flow.
 
   Computations represented by a Future may be yet to be begun, may be ongoing,
   or may have already completed.
   """
-  __metaclass__ = abc.ABCMeta
 
   # NOTE(nathaniel): This isn't the return type that I would want to have if it
   # were up to me. Were this interface being written from scratch, the return
diff --git a/src/python/grpcio/grpc/framework/foundation/relay.py b/src/python/grpcio/grpc/framework/foundation/relay.py
index 9c23946552093dc27173bce191047d90e7926f2d..ff4e2275aefff2adabee5a19c1890345403a03b9 100644
--- a/src/python/grpcio/grpc/framework/foundation/relay.py
+++ b/src/python/grpcio/grpc/framework/foundation/relay.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -46,7 +46,6 @@ class Relay(object):
   would be no reason to use an implementation of this interface instead of a
   thread pool.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def add_value(self, value):
diff --git a/src/python/grpcio/grpc/framework/foundation/stream.py b/src/python/grpcio/grpc/framework/foundation/stream.py
index 75c0cf145b493d4b81e66c8ffc3da30c8d91483a..32a2e52aed9c6c53a8032abb7e59ed9430f55244 100644
--- a/src/python/grpcio/grpc/framework/foundation/stream.py
+++ b/src/python/grpcio/grpc/framework/foundation/stream.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,10 +31,10 @@
 
 import abc
 
+import six
 
-class Consumer(object):
+class Consumer(six.with_metaclass(abc.ABCMeta)):
   """Interface for consumers of finite streams of values or objects."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def consume(self, value):
diff --git a/src/python/grpcio/grpc/framework/interfaces/base/base.py b/src/python/grpcio/grpc/framework/interfaces/base/base.py
index a1e70be5e8d419ecb9c2b63c0c39b458588fee89..69be37e7abf0b74c83ae98244176317aa8a02976 100644
--- a/src/python/grpcio/grpc/framework/interfaces/base/base.py
+++ b/src/python/grpcio/grpc/framework/interfaces/base/base.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -42,6 +42,8 @@ import abc
 import enum
 import threading  # pylint: disable=unused-import
 
+import six
+
 # abandonment is referenced from specification in this module.
 from grpc.framework.foundation import abandonment  # pylint: disable=unused-import
 
@@ -95,7 +97,7 @@ class Outcome(object):
     REMOTE_FAILURE = 'remote failure'
 
 
-class Completion(object):
+class Completion(six.with_metaclass(abc.ABCMeta)):
   """An aggregate of the values exchanged upon operation completion.
 
   Attributes:
@@ -103,12 +105,10 @@ class Completion(object):
     code: A code value for the operation.
     message: A message value for the operation.
   """
-  __metaclass__ = abc.ABCMeta
 
 
-class OperationContext(object):
+class OperationContext(six.with_metaclass(abc.ABCMeta)):
   """Provides operation-related information and action."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def outcome(self):
@@ -162,9 +162,8 @@ class OperationContext(object):
     raise NotImplementedError()
 
 
-class Operator(object):
+class Operator(six.with_metaclass(abc.ABCMeta)):
   """An interface through which to participate in an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def advance(
@@ -184,9 +183,8 @@ class Operator(object):
     """
     raise NotImplementedError()
 
-class ProtocolReceiver(object):
+class ProtocolReceiver(six.with_metaclass(abc.ABCMeta)):
   """A means of receiving protocol values during an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def context(self, protocol_context):
@@ -198,7 +196,7 @@ class ProtocolReceiver(object):
     raise NotImplementedError()
 
 
-class Subscription(object):
+class Subscription(six.with_metaclass(abc.ABCMeta)):
   """Describes customer code's interest in values from the other side.
 
   Attributes:
@@ -216,7 +214,6 @@ class Subscription(object):
       become available during the operation. Must be non-None if kind is
       Kind.FULL.
   """
-  __metaclass__ = abc.ABCMeta
 
   @enum.unique
   class Kind(enum.Enum):
@@ -226,9 +223,8 @@ class Subscription(object):
     FULL = 'full'
 
 
-class Servicer(object):
+class Servicer(six.with_metaclass(abc.ABCMeta)):
   """Interface for service implementations."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def service(self, group, method, context, output_operator):
@@ -255,9 +251,8 @@ class Servicer(object):
     raise NotImplementedError()
 
 
-class End(object):
+class End(six.with_metaclass(abc.ABCMeta)):
   """Common type for entry-point objects on both sides of an operation."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def start(self):
diff --git a/src/python/grpcio/grpc/framework/interfaces/face/face.py b/src/python/grpcio/grpc/framework/interfaces/face/face.py
index 404c3a7937aa58b9f958df1bab27977cc85e6128..b994acecac61fd38e6fa92fef5be35f1b28163c8 100644
--- a/src/python/grpcio/grpc/framework/interfaces/face/face.py
+++ b/src/python/grpcio/grpc/framework/interfaces/face/face.py
@@ -33,6 +33,8 @@ import abc
 import collections
 import enum
 
+import six
+
 # cardinality, style, abandonment, future, and stream are
 # referenced from specification in this module.
 from grpc.framework.common import cardinality  # pylint: disable=unused-import
@@ -96,7 +98,7 @@ class Abortion(
     REMOTE_FAILURE = 'remote failure'
 
 
-class AbortionError(Exception):
+class AbortionError(six.with_metaclass(abc.ABCMeta, Exception)):
   """Common super type for exceptions indicating RPC abortion.
 
     initial_metadata: The initial metadata from the other side of the RPC or
@@ -108,7 +110,6 @@ class AbortionError(Exception):
     details: The details value from the other side of the RPC or None if no
       details value was received.
   """
-  __metaclass__ = abc.ABCMeta
 
   def __init__(self, initial_metadata, terminal_metadata, code, details):
     super(AbortionError, self).__init__()
@@ -150,9 +151,8 @@ class RemoteError(AbortionError):
   """Indicates that an RPC has terminated due to a remote defect."""
 
 
-class RpcContext(object):
+class RpcContext(six.with_metaclass(abc.ABCMeta)):
   """Provides RPC-related information and action."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def is_active(self):
@@ -199,9 +199,8 @@ class RpcContext(object):
     raise NotImplementedError()
 
 
-class Call(RpcContext):
+class Call(six.with_metaclass(abc.ABCMeta, RpcContext)):
   """Invocation-side utility object for an RPC."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def initial_metadata(self):
@@ -256,9 +255,8 @@ class Call(RpcContext):
     raise NotImplementedError()
 
 
-class ServicerContext(RpcContext):
+class ServicerContext(six.with_metaclass(abc.ABCMeta, RpcContext)):
   """A context object passed to method implementations."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def invocation_metadata(self):
@@ -326,9 +324,8 @@ class ServicerContext(RpcContext):
     raise NotImplementedError()
 
 
-class ResponseReceiver(object):
+class ResponseReceiver(six.with_metaclass(abc.ABCMeta)):
   """Invocation-side object used to accept the output of an RPC."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def initial_metadata(self, initial_metadata):
@@ -362,9 +359,8 @@ class ResponseReceiver(object):
     raise NotImplementedError()
 
 
-class UnaryUnaryMultiCallable(object):
+class UnaryUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-unary RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(
@@ -434,9 +430,8 @@ class UnaryUnaryMultiCallable(object):
     raise NotImplementedError()
 
 
-class UnaryStreamMultiCallable(object):
+class UnaryStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a unary-stream RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(self, request, timeout, metadata=None, protocol_options=None):
@@ -480,9 +475,8 @@ class UnaryStreamMultiCallable(object):
     raise NotImplementedError()
 
 
-class StreamUnaryMultiCallable(object):
+class StreamUnaryMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-unary RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(
@@ -553,9 +547,8 @@ class StreamUnaryMultiCallable(object):
     raise NotImplementedError()
 
 
-class StreamStreamMultiCallable(object):
+class StreamStreamMultiCallable(six.with_metaclass(abc.ABCMeta)):
   """Affords invoking a stream-stream RPC in any call style."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def __call__(
@@ -600,7 +593,7 @@ class StreamStreamMultiCallable(object):
     raise NotImplementedError()
 
 
-class MethodImplementation(object):
+class MethodImplementation(six.with_metaclass(abc.ABCMeta)):
   """A sum type that describes a method implementation.
 
   Attributes:
@@ -643,12 +636,10 @@ class MethodImplementation(object):
       is cardinality.Cardinality.STREAM_STREAM and style is
       style.Service.EVENT.
   """
-  __metaclass__ = abc.ABCMeta
 
 
-class MultiMethodImplementation(object):
+class MultiMethodImplementation(six.with_metaclass(abc.ABCMeta)):
   """A general type able to service many methods."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def service(self, group, method, response_consumer, context):
@@ -678,9 +669,8 @@ class MultiMethodImplementation(object):
     raise NotImplementedError()
 
 
-class GenericStub(object):
+class GenericStub(six.with_metaclass(abc.ABCMeta)):
   """Affords RPC invocation via generic methods."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def blocking_unary_unary(
@@ -977,7 +967,7 @@ class GenericStub(object):
     raise NotImplementedError()
 
 
-class DynamicStub(object):
+class DynamicStub(six.with_metaclass(abc.ABCMeta)):
   """Affords RPC invocation via attributes corresponding to afforded methods.
 
   Instances of this type may be scoped to a single group so that attribute
@@ -993,4 +983,3 @@ class DynamicStub(object):
   if the requested attribute is the name of a stream-stream method, the value of
   the attribute will be a StreamStreamMultiCallable with which to invoke an RPC.
   """
-  __metaclass__ = abc.ABCMeta
diff --git a/src/python/grpcio/grpc/framework/interfaces/links/links.py b/src/python/grpcio/grpc/framework/interfaces/links/links.py
index 24f0e3b354517f90bb25ce53e1fd4e981c8a71be..808167935fb2dc59b4f1346abdffbfcb0ebb547d 100644
--- a/src/python/grpcio/grpc/framework/interfaces/links/links.py
+++ b/src/python/grpcio/grpc/framework/interfaces/links/links.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@ import abc
 import collections
 import enum
 
+import six
+
 
 class Protocol(collections.namedtuple('Protocol', ('kind', 'value',))):
   """A sum type for handles to a system that transmits tickets.
@@ -123,9 +125,8 @@ class Ticket(
     REMOTE_FAILURE = 'remote failure'
 
 
-class Link(object):
+class Link(six.with_metaclass(abc.ABCMeta)):
   """Accepts and emits tickets."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def accept_ticket(self, ticket):
diff --git a/src/python/grpcio/tests/unit/_adapter/_proto_scenarios.py b/src/python/grpcio/tests/unit/_adapter/_proto_scenarios.py
index f55a7a23eaea0eeabb71c8452c6baf9ddda903b7..c9f36636b5c040d8c76dc046519abc4dd83635e1 100644
--- a/src/python/grpcio/tests/unit/_adapter/_proto_scenarios.py
+++ b/src/python/grpcio/tests/unit/_adapter/_proto_scenarios.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,12 +32,13 @@
 import abc
 import threading
 
+import six
+
 from tests.unit._junkdrawer import math_pb2
 
 
-class ProtoScenario(object):
+class ProtoScenario(six.with_metaclass(abc.ABCMeta)):
   """An RPC test scenario using protocol buffers."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def method(self):
diff --git a/src/python/grpcio/tests/unit/_links/_proto_scenarios.py b/src/python/grpcio/tests/unit/_links/_proto_scenarios.py
index f69ff51b1679956cf3a945fa45136a289cb3c70b..acd4891390ded6fd27bb37cbce79b5b70d491625 100644
--- a/src/python/grpcio/tests/unit/_links/_proto_scenarios.py
+++ b/src/python/grpcio/tests/unit/_links/_proto_scenarios.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,13 +32,14 @@
 import abc
 import threading
 
+import six
+
 from tests.unit._junkdrawer import math_pb2
 from tests.unit.framework.common import test_constants
 
 
-class ProtoScenario(object):
+class ProtoScenario(six.with_metaclass(abc.ABCMeta)):
   """An RPC test scenario using protocol buffers."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def group_and_method(self):
diff --git a/src/python/grpcio/tests/unit/framework/common/test_control.py b/src/python/grpcio/tests/unit/framework/common/test_control.py
index 8d6eba5c2caabce420300af00b97a709facf0a05..0387668b112644c3bf5fceee2726fd73cb5cad68 100644
--- a/src/python/grpcio/tests/unit/framework/common/test_control.py
+++ b/src/python/grpcio/tests/unit/framework/common/test_control.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@ import abc
 import contextlib
 import threading
 
+import six
+
 
 class Defect(Exception):
   """Simulates a programming defect raised into in a system under test.
@@ -42,7 +44,7 @@ class Defect(Exception):
   """
 
 
-class Control(object):
+class Control(six.with_metaclass(abc.ABCMeta)):
   """An object that accepts program control from a system under test.
 
   Systems under test passed a Control should call its control() method
@@ -51,8 +53,6 @@ class Control(object):
   the system under test to simulate hanging, failing, or functioning.
   """
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def control(self):
     """Potentially does anything."""
diff --git a/src/python/grpcio/tests/unit/framework/common/test_coverage.py b/src/python/grpcio/tests/unit/framework/common/test_coverage.py
index a7ed3582c40bc2ea85d76df4d90e8c1e5fc43c9c..184621fb5c442952dccd89dfb80ca92152a4c67c 100644
--- a/src/python/grpcio/tests/unit/framework/common/test_coverage.py
+++ b/src/python/grpcio/tests/unit/framework/common/test_coverage.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,13 +31,14 @@
 
 import abc
 
+import six
+
 # This code is designed for use with the unittest module.
 # pylint: disable=invalid-name
 
 
-class Coverage(object):
+class Coverage(six.with_metaclass(abc.ABCMeta)):
   """Specification of test coverage."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def testSuccessfulUnaryRequestUnaryResponse(self):
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/base_util.py b/src/python/grpcio/tests/unit/framework/face/testing/base_util.py
index 1df1529b27c009cb0718ec443153df00f01a6552..60ab5bc0fe71570ccc674b863357b61e6b75f0da 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/base_util.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/base_util.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 # interfaces is referenced from specification in this module.
 from grpc.framework.base import util as _base_util
 from grpc.framework.base import implementations
@@ -43,7 +45,7 @@ _POOL_SIZE_LIMIT = 5
 _MAXIMUM_TIMEOUT = 90
 
 
-class LinkedPair(object):
+class LinkedPair(six.with_metaclass(abc.ABCMeta)):
   """A Front and Back that are linked to one another.
 
   Attributes:
@@ -51,8 +53,6 @@ class LinkedPair(object):
     back: An interfaces.Back.
   """
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def shut_down(self):
     """Shuts down this object and releases its resources."""
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/blocking_invocation_inline_service_test_case.py b/src/python/grpcio/tests/unit/framework/face/testing/blocking_invocation_inline_service_test_case.py
index 06135164215e1b2eba479fbda43fb3a20848ced4..2fc67f6292b7a148bfd28313dc2ea13224eeeef5 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/blocking_invocation_inline_service_test_case.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/blocking_invocation_inline_service_test_case.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@
 import abc
 import unittest  # pylint: disable=unused-import
 
+import six
+
 from grpc.framework.face import exceptions
 from tests.unit.framework.common import test_constants
 from tests.unit.framework.face.testing import control
@@ -43,12 +45,12 @@ from tests.unit.framework.face.testing import test_case
 
 
 class BlockingInvocationInlineServiceTestCase(
-    test_case.FaceTestCase, coverage.BlockingCoverage):
+    six.with_metaclass(abc.ABCMeta,
+    test_case.FaceTestCase, coverage.BlockingCoverage)):
   """A test of the Face layer of RPC Framework.
 
   Concrete subclasses must also extend unittest.TestCase.
   """
-  __metaclass__ = abc.ABCMeta
 
   def setUp(self):
     """See unittest.TestCase.setUp for full specification.
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/control.py b/src/python/grpcio/tests/unit/framework/face/testing/control.py
index 3960c4e649590db318223ac44a147c7bf3ffd919..0d40331e1977066e9f3e3c84414f9b186d36c9a2 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/control.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/control.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,8 +33,10 @@ import abc
 import contextlib
 import threading
 
+import six
 
-class Control(object):
+
+class Control(six.with_metaclass(abc.ABCMeta)):
   """An object that accepts program control from a system under test.
 
   Systems under test passed a Control should call its control() method
@@ -43,8 +45,6 @@ class Control(object):
   the system under test to simulate hanging, failing, or functioning.
   """
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def control(self):
     """Potentially does anything."""
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/coverage.py b/src/python/grpcio/tests/unit/framework/face/testing/coverage.py
index f3aca113fe722607d41ea0d50d8a68d474fafe8e..9f5381069d4b77a00c8fbfb6742d5968f5f09ec0 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/coverage.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/coverage.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,15 +31,15 @@
 
 import abc
 
+import six
+
 # These classes are only valid when inherited by unittest.TestCases.
 # pylint: disable=invalid-name
 
 
-class BlockingCoverage(object):
+class BlockingCoverage(six.with_metaclass(abc.ABCMeta)):
   """Specification of test coverage for blocking behaviors."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def testSuccessfulUnaryRequestUnaryResponse(self):
     raise NotImplementedError()
@@ -93,11 +93,9 @@ class BlockingCoverage(object):
     raise NotImplementedError()
 
 
-class FullCoverage(BlockingCoverage):
+class FullCoverage(six.with_metaclass(abc.ABCMeta, BlockingCoverage)):
   """Specification of test coverage for non-blocking behaviors."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def testParallelInvocations(self):
     raise NotImplementedError()
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/event_invocation_synchronous_event_service_test_case.py b/src/python/grpcio/tests/unit/framework/face/testing/event_invocation_synchronous_event_service_test_case.py
index 179f3a2f67c18c82c57f3eacbc9aea1426fbe87f..b707dcdf6ce6308e1c02240335a9a25aa2520e8d 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/event_invocation_synchronous_event_service_test_case.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/event_invocation_synchronous_event_service_test_case.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,8 @@
 import abc
 import unittest
 
+import six
+
 from grpc.framework.face import interfaces
 from tests.unit.framework.common import test_constants
 from tests.unit.framework.face.testing import callback as testing_callback
@@ -43,12 +45,12 @@ from tests.unit.framework.face.testing import test_case
 
 
 class EventInvocationSynchronousEventServiceTestCase(
-    test_case.FaceTestCase, coverage.FullCoverage):
+    six.with_metaclass(abc.ABCMeta,
+    test_case.FaceTestCase, coverage.FullCoverage)):
   """A test of the Face layer of RPC Framework.
 
   Concrete subclasses must also extend unittest.TestCase.
   """
-  __metaclass__ = abc.ABCMeta
 
   def setUp(self):
     """See unittest.TestCase.setUp for full specification.
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py b/src/python/grpcio/tests/unit/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
index 485524a3563fb7509819967e9bfa04531df2cb2e..4d27cbe186cf574593479608dd15e5eaa98e096f 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,8 @@ import contextlib
 import threading
 import unittest
 
+import six
+
 from grpc.framework.face import exceptions
 from grpc.framework.foundation import future
 from grpc.framework.foundation import logging_pool
@@ -74,12 +76,12 @@ class _PauseableIterator(object):
 
 
 class FutureInvocationAsynchronousEventServiceTestCase(
-    test_case.FaceTestCase, coverage.FullCoverage):
+    six.with_metaclass(abc.ABCMeta,
+    test_case.FaceTestCase, coverage.FullCoverage)):
   """A test of the Face layer of RPC Framework.
 
   Concrete subclasses must also extend unittest.TestCase.
   """
-  __metaclass__ = abc.ABCMeta
 
   def setUp(self):
     """See unittest.TestCase.setUp for full specification.
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/interfaces.py b/src/python/grpcio/tests/unit/framework/face/testing/interfaces.py
index 5932dabf1eb98d05a9a33ebfb8ce62d4269a1391..87be836e2d02c0d0469ed72ad7daa401b848d006 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/interfaces.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,13 +31,14 @@
 
 import abc
 
+import six
+
 # cardinality is referenced from specification in this module.
 from grpc.framework.common import cardinality  # pylint: disable=unused-import
 
 
-class Method(object):
+class Method(six.with_metaclass(abc.ABCMeta)):
   """An RPC method to be used in tests of RPC implementations."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def name(self):
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/service.py b/src/python/grpcio/tests/unit/framework/face/testing/service.py
index ac0b89b6eefdabed66b105de77f8d548b29e56ea..dc0f204c04b01e37a6ccaaf8061bbb50c57e7b4e 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/service.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/service.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,16 +31,16 @@
 
 import abc
 
+import six
+
 # interfaces is referenced from specification in this module.
 from grpc.framework.face import interfaces as face_interfaces  # pylint: disable=unused-import
 from tests.unit.framework.face.testing import interfaces
 
 
-class UnaryUnaryTestMethodImplementation(interfaces.Method):
+class UnaryUnaryTestMethodImplementation(six.with_metaclass(abc.ABCMeta, interfaces.Method)):
   """A controllable implementation of a unary-unary RPC method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, request, response_callback, context, control):
     """Services an RPC that accepts one message and produces one message.
@@ -59,11 +59,9 @@ class UnaryUnaryTestMethodImplementation(interfaces.Method):
     raise NotImplementedError()
 
 
-class UnaryUnaryTestMessages(object):
+class UnaryUnaryTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for unary-request-unary-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def request(self):
     """Affords a request message.
@@ -93,11 +91,9 @@ class UnaryUnaryTestMessages(object):
     raise NotImplementedError()
 
 
-class UnaryStreamTestMethodImplementation(interfaces.Method):
+class UnaryStreamTestMethodImplementation(six.with_metaclass(abc.ABCMeta, interfaces.Method)):
   """A controllable implementation of a unary-stream RPC method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, request, response_consumer, context, control):
     """Services an RPC that takes one message and produces a stream of messages.
@@ -116,11 +112,9 @@ class UnaryStreamTestMethodImplementation(interfaces.Method):
     raise NotImplementedError()
 
 
-class UnaryStreamTestMessages(object):
+class UnaryStreamTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for unary-request-stream-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def request(self):
     """Affords a request message.
@@ -150,11 +144,9 @@ class UnaryStreamTestMessages(object):
     raise NotImplementedError()
 
 
-class StreamUnaryTestMethodImplementation(interfaces.Method):
+class StreamUnaryTestMethodImplementation(six.with_metaclass(abc.ABCMeta, interfaces.Method)):
   """A controllable implementation of a stream-unary RPC method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, response_callback, context, control):
     """Services an RPC that takes a stream of messages and produces one message.
@@ -180,11 +172,9 @@ class StreamUnaryTestMethodImplementation(interfaces.Method):
     raise NotImplementedError()
 
 
-class StreamUnaryTestMessages(object):
+class StreamUnaryTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for stream-request-unary-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def requests(self):
     """Affords a sequence of request messages.
@@ -214,11 +204,9 @@ class StreamUnaryTestMessages(object):
     raise NotImplementedError()
 
 
-class StreamStreamTestMethodImplementation(interfaces.Method):
+class StreamStreamTestMethodImplementation(six.with_metaclass(abc.ABCMeta, interfaces.Method)):
   """A controllable implementation of a stream-stream RPC method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, response_consumer, context, control):
     """Services an RPC that accepts and produces streams of messages.
@@ -244,11 +232,9 @@ class StreamStreamTestMethodImplementation(interfaces.Method):
     raise NotImplementedError()
 
 
-class StreamStreamTestMessages(object):
+class StreamStreamTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for stream-request-stream-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def requests(self):
     """Affords a sequence of request messages.
@@ -278,11 +264,9 @@ class StreamStreamTestMessages(object):
     raise NotImplementedError()
 
 
-class TestService(object):
+class TestService(six.with_metaclass(abc.ABCMeta)):
   """A specification of implemented RPC methods to use in tests."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def name(self):
     """Identifies the RPC service name used during the test.
diff --git a/src/python/grpcio/tests/unit/framework/face/testing/test_case.py b/src/python/grpcio/tests/unit/framework/face/testing/test_case.py
index 23d4d919c2377ca7e3558a15368445f765445082..5be9330a77409e02ce336969cde11b8ebe9fa78a 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/test_case.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/test_case.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,18 +31,19 @@
 
 import abc
 
+import six
+
 # face_interfaces and interfaces are referenced in specification in this module.
 from grpc.framework.face import interfaces as face_interfaces  # pylint: disable=unused-import
 from tests.unit.framework.face.testing import interfaces  # pylint: disable=unused-import
 
 
-class FaceTestCase(object):
+class FaceTestCase(six.with_metaclass(abc.ABCMeta)):
   """Describes a test of the Face Layer of RPC Framework.
 
   Concrete subclasses must also inherit from unittest.TestCase and from at least
   one class that defines test methods.
   """
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def set_up_implementation(
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/base/_control.py b/src/python/grpcio/tests/unit/framework/interfaces/base/_control.py
index 38102b198a70fc3e2ef59c627f03e8fe5e6a2052..fe69e63995bb40e904fd18f1027c2c1346489a58 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/base/_control.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/base/_control.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -36,6 +36,8 @@ import random  # pylint: disable=unused-import
 import threading
 import time
 
+import six
+
 from grpc.framework.interfaces.base import base
 from tests.unit.framework.common import test_constants
 from tests.unit.framework.interfaces.base import _sequence
@@ -247,8 +249,7 @@ class Instruction(
     CONCLUDE = 'CONCLUDE'
 
 
-class Controller(object):
-  __metaclass__ = abc.ABCMeta
+class Controller(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def failed(self, message):
@@ -308,8 +309,7 @@ class Controller(object):
     raise NotImplementedError()
 
 
-class ControllerCreator(object):
-  __metaclass__ = abc.ABCMeta
+class ControllerCreator(six.with_metaclass(abc.ABCMeta)):
 
   @abc.abstractmethod
   def name(self):
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/base/test_interfaces.py b/src/python/grpcio/tests/unit/framework/interfaces/base/test_interfaces.py
index 84afd24d478a71f74c0c2493229e6f6a82626e9d..0594cfeb3145e033c5a20677db0a0bf5fb2cf0ba 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/base/test_interfaces.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/base/test_interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,12 +31,13 @@
 
 import abc
 
+import six
+
 from grpc.framework.interfaces.base import base  # pylint: disable=unused-import
 
 
-class Serialization(object):
+class Serialization(six.with_metaclass(abc.ABCMeta)):
   """Specifies serialization and deserialization of test payloads."""
-  __metaclass__ = abc.ABCMeta
 
   def serialize_request(self, request):
     """Serializes a request value used in a test.
@@ -85,9 +86,8 @@ class Serialization(object):
     raise NotImplementedError()
 
 
-class Implementation(object):
+class Implementation(six.with_metaclass(abc.ABCMeta)):
   """Specifies an implementation of the Base layer."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def instantiate(self, serializations, servicer):
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/face/_blocking_invocation_inline_service.py b/src/python/grpcio/tests/unit/framework/interfaces/face/_blocking_invocation_inline_service.py
index c8a3a1bc7499ae6a8311eea5aed668901ef9b700..a47fcd368167147ec39f21e8339cce7d0cb4508f 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/face/_blocking_invocation_inline_service.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/face/_blocking_invocation_inline_service.py
@@ -34,6 +34,8 @@ import itertools
 import unittest
 from concurrent import futures
 
+import six
+
 # test_interfaces is referenced from specification in this module.
 from grpc.framework.foundation import logging_pool
 from grpc.framework.interfaces.face import face
@@ -46,14 +48,13 @@ from tests.unit.framework.interfaces.face import _stock_service
 from tests.unit.framework.interfaces.face import test_interfaces  # pylint: disable=unused-import
 
 
-class TestCase(test_coverage.Coverage, unittest.TestCase):
+class TestCase(six.with_metaclass(abc.ABCMeta, test_coverage.Coverage, unittest.TestCase)):
   """A test of the Face layer of RPC Framework.
 
   Concrete subclasses must have an "implementation" attribute of type
   test_interfaces.Implementation and an "invoker_constructor" attribute of type
   _invocation.InvokerConstructor.
   """
-  __metaclass__ = abc.ABCMeta
 
   NAME = 'BlockingInvocationInlineServiceTest'
 
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/face/_future_invocation_asynchronous_event_service.py b/src/python/grpcio/tests/unit/framework/interfaces/face/_future_invocation_asynchronous_event_service.py
index 1d36a931e8c1f1384c63a8a1c200a2c6efc990ee..fb4bee6f86fc588e327b92189edd409064130b16 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/face/_future_invocation_asynchronous_event_service.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/face/_future_invocation_asynchronous_event_service.py
@@ -36,6 +36,8 @@ import threading
 import unittest
 from concurrent import futures
 
+import six
+
 # test_interfaces is referenced from specification in this module.
 from grpc.framework.foundation import logging_pool
 from grpc.framework.interfaces.face import face
@@ -104,14 +106,13 @@ class _Callback(object):
           self._condition.wait()
 
 
-class TestCase(test_coverage.Coverage, unittest.TestCase):
+class TestCase(six.with_metaclass(abc.ABCMeta, test_coverage.Coverage, unittest.TestCase)):
   """A test of the Face layer of RPC Framework.
 
   Concrete subclasses must have an "implementation" attribute of type
   test_interfaces.Implementation and an "invoker_constructor" attribute of type
   _invocation.InvokerConstructor.
   """
-  __metaclass__ = abc.ABCMeta
 
   NAME = 'FutureInvocationAsynchronousEventServiceTest'
 
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/face/_invocation.py b/src/python/grpcio/tests/unit/framework/interfaces/face/_invocation.py
index 448e845a08ddb4859dea24d19515a2f09e3fc5f6..ff38dc2ece365f72e8b3dc2708e3ba6070d5c36f 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/face/_invocation.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/face/_invocation.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,6 +31,8 @@
 
 import abc
 
+import six
+
 from grpc.framework.common import cardinality
 
 _CARDINALITY_TO_GENERIC_BLOCKING_BEHAVIOR = {
@@ -62,9 +64,8 @@ _CARDINALITY_TO_MULTI_CALLABLE_ATTRIBUTE = {
 }
 
 
-class Invoker(object):
+class Invoker(six.with_metaclass(abc.ABCMeta)):
   """A type used to invoke test RPCs."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def blocking(self, group, name):
@@ -82,9 +83,8 @@ class Invoker(object):
     raise NotImplementedError()
 
 
-class InvokerConstructor(object):
+class InvokerConstructor(six.with_metaclass(abc.ABCMeta)):
   """A type used to create Invokers."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def name(self):
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/face/_service.py b/src/python/grpcio/tests/unit/framework/interfaces/face/_service.py
index 28941e2ad0319c02a74b49668044f67419d1dbb3..bec8d5113c17ac153bb31ff4311e24922ab702c7 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/face/_service.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/face/_service.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,16 +31,16 @@
 
 import abc
 
+import six
+
 # face is referenced from specification in this module.
 from grpc.framework.interfaces.face import face  # pylint: disable=unused-import
 from tests.unit.framework.interfaces.face import test_interfaces
 
 
-class UnaryUnaryTestMethodImplementation(test_interfaces.Method):
+class UnaryUnaryTestMethodImplementation(six.with_metaclass(abc.ABCMeta, test_interfaces.Method)):
   """A controllable implementation of a unary-unary method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, request, response_callback, context, control):
     """Services an RPC that accepts one message and produces one message.
@@ -59,11 +59,9 @@ class UnaryUnaryTestMethodImplementation(test_interfaces.Method):
     raise NotImplementedError()
 
 
-class UnaryUnaryTestMessages(object):
+class UnaryUnaryTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for unary-request-unary-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def request(self):
     """Affords a request message.
@@ -93,11 +91,9 @@ class UnaryUnaryTestMessages(object):
     raise NotImplementedError()
 
 
-class UnaryStreamTestMethodImplementation(test_interfaces.Method):
+class UnaryStreamTestMethodImplementation(six.with_metaclass(abc.ABCMeta, test_interfaces.Method)):
   """A controllable implementation of a unary-stream method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, request, response_consumer, context, control):
     """Services an RPC that takes one message and produces a stream of messages.
@@ -116,11 +112,9 @@ class UnaryStreamTestMethodImplementation(test_interfaces.Method):
     raise NotImplementedError()
 
 
-class UnaryStreamTestMessages(object):
+class UnaryStreamTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for unary-request-stream-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def request(self):
     """Affords a request message.
@@ -150,11 +144,9 @@ class UnaryStreamTestMessages(object):
     raise NotImplementedError()
 
 
-class StreamUnaryTestMethodImplementation(test_interfaces.Method):
+class StreamUnaryTestMethodImplementation(six.with_metaclass(abc.ABCMeta, test_interfaces.Method)):
   """A controllable implementation of a stream-unary method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, response_callback, context, control):
     """Services an RPC that takes a stream of messages and produces one message.
@@ -180,11 +172,9 @@ class StreamUnaryTestMethodImplementation(test_interfaces.Method):
     raise NotImplementedError()
 
 
-class StreamUnaryTestMessages(object):
+class StreamUnaryTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for stream-request-unary-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def requests(self):
     """Affords a sequence of request messages.
@@ -214,11 +204,9 @@ class StreamUnaryTestMessages(object):
     raise NotImplementedError()
 
 
-class StreamStreamTestMethodImplementation(test_interfaces.Method):
+class StreamStreamTestMethodImplementation(six.with_metaclass(abc.ABCMeta, test_interfaces.Method)):
   """A controllable implementation of a stream-stream method."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def service(self, response_consumer, context, control):
     """Services an RPC that accepts and produces streams of messages.
@@ -244,11 +232,9 @@ class StreamStreamTestMethodImplementation(test_interfaces.Method):
     raise NotImplementedError()
 
 
-class StreamStreamTestMessages(object):
+class StreamStreamTestMessages(six.with_metaclass(abc.ABCMeta)):
   """A type for stream-request-stream-response message pairings."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def requests(self):
     """Affords a sequence of request messages.
@@ -278,11 +264,9 @@ class StreamStreamTestMessages(object):
     raise NotImplementedError()
 
 
-class TestService(object):
+class TestService(six.with_metaclass(abc.ABCMeta)):
   """A specification of implemented methods to use in tests."""
 
-  __metaclass__ = abc.ABCMeta
-
   @abc.abstractmethod
   def unary_unary_scenarios(self):
     """Affords unary-request-unary-response test methods and their messages.
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/face/test_interfaces.py b/src/python/grpcio/tests/unit/framework/interfaces/face/test_interfaces.py
index b2b5c10fa6f733918509cf4bbb8cac0032bb5485..a5e28b79425d3e433cd3da7f8187a53786ea3857 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/face/test_interfaces.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/face/test_interfaces.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -31,13 +31,14 @@
 
 import abc
 
+import six
+
 from grpc.framework.common import cardinality  # pylint: disable=unused-import
 from grpc.framework.interfaces.face import face  # pylint: disable=unused-import
 
 
-class Method(object):
+class Method(six.with_metaclass(abc.ABCMeta)):
   """Specifies a method to be used in tests."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def group(self):
@@ -126,9 +127,8 @@ class Method(object):
     raise NotImplementedError()
 
 
-class Implementation(object):
+class Implementation(six.with_metaclass(abc.ABCMeta)):
   """Specifies an implementation of the Face layer."""
-  __metaclass__ = abc.ABCMeta
 
   @abc.abstractmethod
   def instantiate(
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/links/test_cases.py b/src/python/grpcio/tests/unit/framework/interfaces/links/test_cases.py
index dace6c23f3f0b9b50f41caa391f9e4fdf6aded53..2283e79f0abcd06ab3572cb17e15d092c7cf540d 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/links/test_cases.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/links/test_cases.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,8 @@
 import abc
 import unittest  # pylint: disable=unused-import
 
+import six
+
 from grpc.framework.interfaces.links import links
 from tests.unit.framework.common import test_constants
 from tests.unit.framework.interfaces.links import test_utilities
@@ -58,13 +60,12 @@ _TRANSMISSION_GROUP = 'test.Group'
 _TRANSMISSION_METHOD = 'TestMethod'
 
 
-class TransmissionTest(object):
+class TransmissionTest(six.with_metaclass(abc.ABCMeta)):
   """Tests ticket transmission between two connected links.
 
   This class must be mixed into a unittest.TestCase that implements the abstract
   methods it provides.
   """
-  __metaclass__ = abc.ABCMeta
 
   # This is a unittest.TestCase mix-in.
   # pylint: disable=invalid-name