diff -Nru google_auth-2.45.0.orig/tests/compute_engine/test_credentials.py google_auth-2.45.0/tests/compute_engine/test_credentials.py
--- google_auth-2.45.0.orig/tests/compute_engine/test_credentials.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/compute_engine/test_credentials.py	2026-01-05 11:42:16.623606323 +0100
@@ -15,7 +15,7 @@
 import datetime
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 import responses  # type: ignore
 
diff -Nru google_auth-2.45.0.orig/tests/compute_engine/test__metadata.py google_auth-2.45.0/tests/compute_engine/test__metadata.py
--- google_auth-2.45.0.orig/tests/compute_engine/test__metadata.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/compute_engine/test__metadata.py	2026-01-05 11:42:16.627996539 +0100
@@ -18,7 +18,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 import requests
 
diff -Nru google_auth-2.45.0.orig/tests/compute_engine/test__mtls.py google_auth-2.45.0/tests/compute_engine/test__mtls.py
--- google_auth-2.45.0.orig/tests/compute_engine/test__mtls.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/compute_engine/test__mtls.py	2026-01-05 11:42:16.626031994 +0100
@@ -17,7 +17,7 @@
 
 from pathlib import Path
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 import requests
 
diff -Nru google_auth-2.45.0.orig/tests/conftest.py google_auth-2.45.0/tests/conftest.py
--- google_auth-2.45.0.orig/tests/conftest.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/conftest.py	2026-01-05 11:42:16.533246846 +0100
@@ -15,7 +15,7 @@
 import os
 import sys
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 
diff -Nru google_auth-2.45.0.orig/tests/crypt/test__python_rsa.py google_auth-2.45.0/tests/crypt/test__python_rsa.py
--- google_auth-2.45.0.orig/tests/crypt/test__python_rsa.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/crypt/test__python_rsa.py	2026-01-05 11:42:16.654083195 +0100
@@ -16,7 +16,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 from pyasn1_modules import pem  # type: ignore
 import pytest  # type: ignore
 import rsa  # type: ignore
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_challenges.py google_auth-2.45.0/tests/oauth2/test_challenges.py
--- google_auth-2.45.0.orig/tests/oauth2/test_challenges.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_challenges.py	2026-01-05 11:42:16.601584221 +0100
@@ -18,7 +18,7 @@
 import os
 import sys
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 import pyu2f  # type: ignore
 
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test__client.py google_auth-2.45.0/tests/oauth2/test__client.py
--- google_auth-2.45.0.orig/tests/oauth2/test__client.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test__client.py	2026-01-05 11:42:16.589400013 +0100
@@ -18,7 +18,7 @@
 import os
 import urllib
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_credentials.py google_auth-2.45.0/tests/oauth2/test_credentials.py
--- google_auth-2.45.0.orig/tests/oauth2/test_credentials.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_credentials.py	2026-01-05 11:42:16.594584105 +0100
@@ -18,7 +18,7 @@
 import pickle
 import sys
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_gdch_credentials.py google_auth-2.45.0/tests/oauth2/test_gdch_credentials.py
--- google_auth-2.45.0.orig/tests/oauth2/test_gdch_credentials.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_gdch_credentials.py	2026-01-05 11:42:16.582005367 +0100
@@ -17,7 +17,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 import requests
 
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_id_token.py google_auth-2.45.0/tests/oauth2/test_id_token.py
--- google_auth-2.45.0.orig/tests/oauth2/test_id_token.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_id_token.py	2026-01-05 11:42:16.584583939 +0100
@@ -15,7 +15,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import environment_vars
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_reauth.py google_auth-2.45.0/tests/oauth2/test_reauth.py
--- google_auth-2.45.0.orig/tests/oauth2/test_reauth.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_reauth.py	2026-01-05 11:42:16.597276375 +0100
@@ -14,7 +14,7 @@
 
 import copy
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import exceptions
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_service_account.py google_auth-2.45.0/tests/oauth2/test_service_account.py
--- google_auth-2.45.0.orig/tests/oauth2/test_service_account.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_service_account.py	2026-01-05 11:42:16.592584072 +0100
@@ -16,7 +16,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_sts.py google_auth-2.45.0/tests/oauth2/test_sts.py
--- google_auth-2.45.0.orig/tests/oauth2/test_sts.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_sts.py	2026-01-05 11:42:16.603967874 +0100
@@ -16,7 +16,7 @@
 import json
 import urllib
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import exceptions
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_webauthn_handler_factory.py google_auth-2.45.0/tests/oauth2/test_webauthn_handler_factory.py
--- google_auth-2.45.0.orig/tests/oauth2/test_webauthn_handler_factory.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_webauthn_handler_factory.py	2026-01-05 11:42:16.609560836 +0100
@@ -1,4 +1,4 @@
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.oauth2 import webauthn_handler
diff -Nru google_auth-2.45.0.orig/tests/oauth2/test_webauthn_handler.py google_auth-2.45.0/tests/oauth2/test_webauthn_handler.py
--- google_auth-2.45.0.orig/tests/oauth2/test_webauthn_handler.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/oauth2/test_webauthn_handler.py	2026-01-05 11:42:16.586583972 +0100
@@ -1,7 +1,7 @@
 import json
 import struct
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import exceptions
diff -Nru google_auth-2.45.0.orig/tests/test_agent_identity_utils.py google_auth-2.45.0/tests/test_agent_identity_utils.py
--- google_auth-2.45.0.orig/tests/test_agent_identity_utils.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_agent_identity_utils.py	2026-01-05 11:42:16.658622002 +0100
@@ -18,7 +18,7 @@
 import urllib.parse
 
 from cryptography import x509
-import mock
+from unittest import mock
 import pytest
 
 from google.auth import _agent_identity_utils
diff -Nru google_auth-2.45.0.orig/tests/test_app_engine.py google_auth-2.45.0/tests/test_app_engine.py
--- google_auth-2.45.0.orig/tests/test_app_engine.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_app_engine.py	2026-01-05 11:42:16.568362885 +0100
@@ -14,7 +14,7 @@
 
 import datetime
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import app_engine
diff -Nru google_auth-2.45.0.orig/tests/test_aws.py google_auth-2.45.0/tests/test_aws.py
--- google_auth-2.45.0.orig/tests/test_aws.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_aws.py	2026-01-05 11:42:16.675585451 +0100
@@ -18,7 +18,7 @@
 import os
 import urllib.parse
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers, external_account
diff -Nru google_auth-2.45.0.orig/tests/test__cloud_sdk.py google_auth-2.45.0/tests/test__cloud_sdk.py
--- google_auth-2.45.0.orig/tests/test__cloud_sdk.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test__cloud_sdk.py	2026-01-05 11:42:16.576167661 +0100
@@ -18,7 +18,7 @@
 import subprocess
 import sys
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _cloud_sdk
diff -Nru google_auth-2.45.0.orig/tests/test_credentials.py google_auth-2.45.0/tests/test_credentials.py
--- google_auth-2.45.0.orig/tests/test_credentials.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_credentials.py	2026-01-05 11:42:16.613640791 +0100
@@ -15,7 +15,7 @@
 import datetime
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test__default.py google_auth-2.45.0/tests/test__default.py
--- google_auth-2.45.0.orig/tests/test__default.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test__default.py	2026-01-05 11:42:16.616584471 +0100
@@ -16,7 +16,7 @@
 import os
 import warnings
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _default
diff -Nru google_auth-2.45.0.orig/tests/test_downscoped.py google_auth-2.45.0/tests/test_downscoped.py
--- google_auth-2.45.0.orig/tests/test_downscoped.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test_downscoped.py	2026-01-05 11:42:16.621323204 +0100
@@ -17,7 +17,7 @@
 import json
 import urllib
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test__exponential_backoff.py google_auth-2.45.0/tests/test__exponential_backoff.py
--- google_auth-2.45.0.orig/tests/test__exponential_backoff.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test__exponential_backoff.py	2026-01-05 11:42:16.523969040 +0100
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _exponential_backoff
diff -Nru google_auth-2.45.0.orig/tests/test_external_account_authorized_user.py google_auth-2.45.0/tests/test_external_account_authorized_user.py
--- google_auth-2.45.0.orig/tests/test_external_account_authorized_user.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_external_account_authorized_user.py	2026-01-05 11:42:16.618826678 +0100
@@ -17,7 +17,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import environment_vars
diff -Nru google_auth-2.45.0.orig/tests/test_external_account.py google_auth-2.45.0/tests/test_external_account.py
--- google_auth-2.45.0.orig/tests/test_external_account.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_external_account.py	2026-01-05 11:42:16.527582992 +0100
@@ -18,7 +18,7 @@
 import os
 import urllib
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test_iam.py google_auth-2.45.0/tests/test_iam.py
--- google_auth-2.45.0.orig/tests/test_iam.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_iam.py	2026-01-05 11:42:16.631913394 +0100
@@ -17,7 +17,7 @@
 import http.client as http_client
 import json
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test_identity_pool.py google_auth-2.45.0/tests/test_identity_pool.py
--- google_auth-2.45.0.orig/tests/test_identity_pool.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test_identity_pool.py	2026-01-05 11:42:16.633584753 +0100
@@ -19,7 +19,7 @@
 import os
 import urllib
 
-import mock
+from unittest import mock
 from OpenSSL import crypto
 import pytest  # type: ignore
 
diff -Nru google_auth-2.45.0.orig/tests/test_impersonated_credentials.py google_auth-2.45.0/tests/test_impersonated_credentials.py
--- google_auth-2.45.0.orig/tests/test_impersonated_credentials.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_impersonated_credentials.py	2026-01-05 11:42:16.668585335 +0100
@@ -18,7 +18,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test_jwt.py google_auth-2.45.0/tests/test_jwt.py
--- google_auth-2.45.0.orig/tests/test_jwt.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test_jwt.py	2026-01-05 11:42:16.636848625 +0100
@@ -17,7 +17,7 @@
 import json
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/test_metrics.py google_auth-2.45.0/tests/test_metrics.py
--- google_auth-2.45.0.orig/tests/test_metrics.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test_metrics.py	2026-01-05 11:42:16.580139521 +0100
@@ -14,7 +14,7 @@
 
 import platform
 
-import mock
+from unittest import mock
 
 from google.auth import metrics
 from google.auth import version
diff -Nru google_auth-2.45.0.orig/tests/test__oauth2client.py google_auth-2.45.0/tests/test__oauth2client.py
--- google_auth-2.45.0.orig/tests/test__oauth2client.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/test__oauth2client.py	2026-01-05 11:42:16.570240675 +0100
@@ -17,7 +17,7 @@
 import os
 import sys
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 try:
diff -Nru google_auth-2.45.0.orig/tests/test_pluggable.py google_auth-2.45.0/tests/test_pluggable.py
--- google_auth-2.45.0.orig/tests/test_pluggable.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test_pluggable.py	2026-01-05 11:42:16.671596074 +0100
@@ -16,7 +16,7 @@
 import os
 import subprocess
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import exceptions
diff -Nru google_auth-2.45.0.orig/tests/test__refresh_worker.py google_auth-2.45.0/tests/test__refresh_worker.py
--- google_auth-2.45.0.orig/tests/test__refresh_worker.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/test__refresh_worker.py	2026-01-05 11:42:16.655941717 +0100
@@ -17,7 +17,7 @@
 import threading
 import time
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _refresh_worker, credentials, exceptions
diff -Nru google_auth-2.45.0.orig/tests/transport/aio/test_aiohttp.py google_auth-2.45.0/tests/transport/aio/test_aiohttp.py
--- google_auth-2.45.0.orig/tests/transport/aio/test_aiohttp.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/transport/aio/test_aiohttp.py	2026-01-05 11:42:16.542435532 +0100
@@ -15,7 +15,7 @@
 import asyncio
 
 from aioresponses import aioresponses  # type: ignore
-from mock import AsyncMock, Mock, patch
+from unittest.mock import AsyncMock, Mock, patch
 import pytest  # type: ignore
 import pytest_asyncio  # type: ignore
 
diff -Nru google_auth-2.45.0.orig/tests/transport/aio/test_sessions.py google_auth-2.45.0/tests/transport/aio/test_sessions.py
--- google_auth-2.45.0.orig/tests/transport/aio/test_sessions.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/transport/aio/test_sessions.py	2026-01-05 11:42:16.539312365 +0100
@@ -16,7 +16,7 @@
 from typing import AsyncGenerator
 
 from aioresponses import aioresponses  # type: ignore
-from mock import Mock, patch
+from unittest.mock import Mock, patch
 import pytest  # type: ignore
 
 from google.auth.aio.credentials import AnonymousCredentials
diff -Nru google_auth-2.45.0.orig/tests/transport/test__custom_tls_signer.py google_auth-2.45.0/tests/transport/test__custom_tls_signer.py
--- google_auth-2.45.0.orig/tests/transport/test__custom_tls_signer.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test__custom_tls_signer.py	2026-01-05 11:42:16.545511419 +0100
@@ -15,7 +15,7 @@
 import ctypes
 import os
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 from requests.packages.urllib3.util.ssl_ import create_urllib3_context  # type: ignore
 import urllib3.contrib.pyopenssl  # type: ignore
diff -Nru google_auth-2.45.0.orig/tests/transport/test_grpc.py google_auth-2.45.0/tests/transport/test_grpc.py
--- google_auth-2.45.0.orig/tests/transport/test_grpc.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test_grpc.py	2026-01-05 11:42:16.548583341 +0100
@@ -16,7 +16,7 @@
 import os
 import time
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import _helpers
diff -Nru google_auth-2.45.0.orig/tests/transport/test__mtls_helper.py google_auth-2.45.0/tests/transport/test__mtls_helper.py
--- google_auth-2.45.0.orig/tests/transport/test__mtls_helper.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test__mtls_helper.py	2026-01-05 11:42:16.554347244 +0100
@@ -16,7 +16,7 @@
 import os
 import re
 
-import mock
+from unittest import mock
 from OpenSSL import crypto
 import pytest  # type: ignore
 
diff -Nru google_auth-2.45.0.orig/tests/transport/test_mtls.py google_auth-2.45.0/tests/transport/test_mtls.py
--- google_auth-2.45.0.orig/tests/transport/test_mtls.py	2025-12-15 23:54:24.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test_mtls.py	2026-01-05 11:42:16.557298333 +0100
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 import pytest  # type: ignore
 
 from google.auth import exceptions
diff -Nru google_auth-2.45.0.orig/tests/transport/test_requests.py google_auth-2.45.0/tests/transport/test_requests.py
--- google_auth-2.45.0.orig/tests/transport/test_requests.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test_requests.py	2026-01-05 11:42:16.560338823 +0100
@@ -19,7 +19,7 @@
 import sys
 
 import freezegun
-import mock
+from unittest import mock
 import OpenSSL
 import pytest  # type: ignore
 import requests
diff -Nru google_auth-2.45.0.orig/tests/transport/test_urllib3.py google_auth-2.45.0/tests/transport/test_urllib3.py
--- google_auth-2.45.0.orig/tests/transport/test_urllib3.py	2025-12-15 23:54:25.000000000 +0100
+++ google_auth-2.45.0/tests/transport/test_urllib3.py	2026-01-05 11:42:16.536146758 +0100
@@ -16,7 +16,7 @@
 import os
 import sys
 
-import mock
+from unittest import mock
 import OpenSSL
 import pytest  # type: ignore
 import urllib3  # type: ignore