Index: ZEO-5.2.3/src/ZEO/tests/testZEO.py
===================================================================
--- ZEO-5.2.3.orig/src/ZEO/tests/testZEO.py	2021-04-29 11:25:08.000000000 +0200
+++ ZEO-5.2.3/src/ZEO/tests/testZEO.py	2021-09-24 11:27:58.067122104 +0200
@@ -80,7 +80,10 @@ class CreativeGetState(persistent.Persis
 class Test_convenience_functions(unittest.TestCase):
 
     def test_ZEO_client_convenience(self):
-        import mock
+        try:
+           from unittest import mock as mock
+        except ImportError:
+           import mock
         import ZEO
 
         client_thread = mock.Mock(
@@ -90,7 +93,10 @@ class Test_convenience_functions(unittes
         self.assertIsInstance(client, ClientStorage)
 
     def test_ZEO_DB_convenience_ok(self):
-        import mock
+        try:
+           from unittest import mock as mock
+        except ImportError:
+           import mock
         import ZEO
 
         client_mock = mock.Mock(spec=['close'])
@@ -108,7 +114,10 @@ class Test_convenience_functions(unittes
         client_mock.close.assert_not_called()
 
     def test_ZEO_DB_convenience_error(self):
-        import mock
+        try:
+           from unittest import mock as mock
+        except ImportError:
+           import mock
         import ZEO
 
         client_mock = mock.Mock(spec=['close'])
@@ -126,7 +135,10 @@ class Test_convenience_functions(unittes
         client_mock.close.assert_called_once()
 
     def test_ZEO_connection_convenience_ok(self):
-        import mock
+        try:
+           from unittest import mock as mock
+        except ImportError:
+           import mock
         import ZEO
 
         ret = object()
@@ -145,7 +157,10 @@ class Test_convenience_functions(unittes
         DB_mock.close.assert_not_called()
 
     def test_ZEO_connection_convenience_value(self):
-        import mock
+        try:
+           from unittest import mock as mock
+        except ImportError:
+           import mock
         import ZEO
 
         DB_mock = mock.Mock(spec=[
Index: ZEO-5.2.3/src/ZEO/tests/testZEOServer.py
===================================================================
--- ZEO-5.2.3.orig/src/ZEO/tests/testZEOServer.py	2020-07-24 12:54:40.000000000 +0200
+++ ZEO-5.2.3/src/ZEO/tests/testZEOServer.py	2021-09-24 11:28:21.655258841 +0200
@@ -1,6 +1,9 @@
 import unittest
 
-import mock
+try:
+   from unittest import mock as mock
+except ImportError:
+   import mock
 import os
 
 from ZEO._compat import PY3
Index: ZEO-5.2.3/src/ZEO/tests/testssl.py
===================================================================
--- ZEO-5.2.3.orig/src/ZEO/tests/testssl.py	2020-07-24 12:54:40.000000000 +0200
+++ ZEO-5.2.3/src/ZEO/tests/testssl.py	2021-09-24 11:28:36.887347135 +0200
@@ -1,9 +1,12 @@
 from .._compat import PY3
 
-import mock
 import os
 import ssl
 import unittest
+try:
+  from unittest import mock as mock
+except ImportError:
+  import mock
 from ZODB.config import storageFromString
 
 from ..Exceptions import ClientDisconnected
Index: ZEO-5.2.3/src/ZEO/asyncio/tests.py
===================================================================
--- ZEO-5.2.3.orig/src/ZEO/asyncio/tests.py	2021-04-29 11:25:08.000000000 +0200
+++ ZEO-5.2.3/src/ZEO/asyncio/tests.py	2021-09-24 11:20:02.132363111 +0200
@@ -7,7 +7,10 @@ else:
 
 from zope.testing import setupstack
 from concurrent.futures import Future
-import mock
+try:
+  from unittest import mock as mock
+except ImportError:
+  import mock
 from ZODB.POSException import ReadOnlyError
 from ZODB.utils import maxtid, RLock