diff --git a/src/python/src/grpc/_adapter/fore.py b/src/python/src/grpc/_adapter/fore.py
index 05016cdaf3130459c6291c656d08bb0e4060c8e1..69e145e3f61529acb78752a2c48cdae2b92d93f7 100644
--- a/src/python/src/grpc/_adapter/fore.py
+++ b/src/python/src/grpc/_adapter/fore.py
@@ -41,7 +41,7 @@ from grpc.framework.base import null
 from grpc.framework.foundation import activated
 from grpc.framework.foundation import logging_pool
 
-_THREAD_POOL_SIZE = 100
+_THREAD_POOL_SIZE = 10
 
 
 @enum.unique
diff --git a/src/python/src/grpc/_adapter/rear.py b/src/python/src/grpc/_adapter/rear.py
index dd0a486117fbfcec711ccaf4b7152b2951b575fd..b3b0b4ed32987db61a553eb7b50263c1cd86af42 100644
--- a/src/python/src/grpc/_adapter/rear.py
+++ b/src/python/src/grpc/_adapter/rear.py
@@ -41,7 +41,7 @@ from grpc.framework.base import null
 from grpc.framework.foundation import activated
 from grpc.framework.foundation import logging_pool
 
-_THREAD_POOL_SIZE = 100
+_THREAD_POOL_SIZE = 10
 
 _INVOCATION_EVENT_KINDS = (
     _low.Event.Kind.METADATA_ACCEPTED,
diff --git a/src/python/src/grpc/framework/base/implementations_test.py b/src/python/src/grpc/framework/base/implementations_test.py
index 11e49caf756dc46363feeee86042cc69b5c66905..d40bb4d92eebfbde19c2552d62aa48156596fd68 100644
--- a/src/python/src/grpc/framework/base/implementations_test.py
+++ b/src/python/src/grpc/framework/base/implementations_test.py
@@ -36,7 +36,7 @@ from grpc.framework.base import interfaces_test_case
 from grpc.framework.base import util
 from grpc.framework.foundation import logging_pool
 
-POOL_MAX_WORKERS = 100
+POOL_MAX_WORKERS = 10
 DEFAULT_TIMEOUT = 30
 MAXIMUM_TIMEOUT = 60
 
diff --git a/src/python/src/grpc/framework/face/_test_case.py b/src/python/src/grpc/framework/face/_test_case.py
index b3a012db001ef44046ff13ee6247129f1bf7a62f..642d500628de084a2402a02695a86fbac3d52da0 100644
--- a/src/python/src/grpc/framework/face/_test_case.py
+++ b/src/python/src/grpc/framework/face/_test_case.py
@@ -35,7 +35,7 @@ from grpc.framework.face.testing import test_case
 from grpc.framework.foundation import logging_pool
 
 _TIMEOUT = 3
-_MAXIMUM_POOL_SIZE = 100
+_MAXIMUM_POOL_SIZE = 10
 
 
 class FaceTestCase(test_case.FaceTestCase):
diff --git a/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py b/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
index 0d51b64f1b3b51f4ac0275b83967a68be9e57edf..21bf9a42486a651ad81734e4e18dea82192ca977 100644
--- a/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
+++ b/src/python/src/grpc/framework/face/testing/future_invocation_asynchronous_event_service_test_case.py
@@ -44,7 +44,7 @@ from grpc.framework.foundation import future
 from grpc.framework.foundation import logging_pool
 
 _TIMEOUT = 3
-_MAXIMUM_POOL_SIZE = 100
+_MAXIMUM_POOL_SIZE = 10
 
 
 class _PauseableIterator(object):