1 files changed, 4 insertions, 6 deletions
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 f3aca113fe..3c88b7841a 100644
--- a/src/python/grpcio/tests/unit/framework/face/testing/coverage.py
+++ b/src/python/grpcio/tests/unit/framework/face/testing/coverage.py
@@ -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()