diff -ur transaction-3.0.1/setup.py transaction-3.0.1.sal/setup.py
--- transaction-3.0.1/setup.py	1970-01-01 01:00:00.000000000 +0100
+++ transaction-3.0.1.sal/setup.py	2022-04-21 09:55:53.338715279 +0200
@@ -25,7 +25,7 @@
 
 README = _read_file('README.rst') + '\n\n' + _read_file('CHANGES.rst')
 
-tests_require = ['mock']
+tests_require = ['unittest.mock']
 
 setup(name='transaction',
       version=version,
diff -ur transaction-3.0.1/src/transaction/tests/test__manager.py transaction-3.0.1.sal/src/transaction/tests/test__manager.py
--- transaction-3.0.1/src/transaction/tests/test__manager.py	1970-01-01 01:00:00.000000000 +0100
+++ transaction-3.0.1.sal/src/transaction/tests/test__manager.py	2022-04-21 09:56:53.648218742 +0200
@@ -11,7 +11,7 @@
 # FOR A PARTICULAR PURPOSE
 #
 ##############################################################################
-import mock
+import unittest.mock
 import unittest
 
 import zope.interface.verify
@@ -671,15 +671,15 @@
         # If a datamanager registers for synchonization after a
         # transaction has started, we should call newTransaction so it
         # can do necessry setup.
-        import mock
+        import unittest.mock
         from .. import TransactionManager
         manager = TransactionManager()
-        sync1 = mock.MagicMock()
+        sync1 = unittest.mock.MagicMock()
         manager.registerSynch(sync1)
         sync1.newTransaction.assert_not_called()
         t = manager.begin()
         sync1.newTransaction.assert_called_with(t)
-        sync2 = mock.MagicMock()
+        sync2 = unittest.mock.MagicMock()
         manager.registerSynch(sync2)
         sync2.newTransaction.assert_called_with(t)
 
@@ -746,8 +746,8 @@
     def test_sync_registration_thread_local_manager(self):
         import transaction
 
-        sync = mock.MagicMock()
-        sync2 = mock.MagicMock()
+        sync = unittest.mock.MagicMock()
+        sync2 = unittest.mock.MagicMock()
         self.assertFalse(transaction.manager.registeredSynchs())
         transaction.manager.registerSynch(sync)
         self.assertTrue(transaction.manager.registeredSynchs())
diff -ur transaction-3.0.1/src/transaction.egg-info/requires.txt transaction-3.0.1.sal/src/transaction.egg-info/requires.txt
--- transaction-3.0.1/src/transaction.egg-info/requires.txt	1970-01-01 01:00:00.000000000 +0100
+++ transaction-3.0.1.sal/src/transaction.egg-info/requires.txt	2022-04-21 09:56:25.300922162 +0200
@@ -5,9 +5,9 @@
 repoze.sphinx.autointerface
 
 [test]
-mock
+unittest.mock
 
 [testing]
 nose
 coverage
-mock
+unittest.mock