diff --git a/docs/changelog.rst b/docs/changelog.rst
index 17e90db..f149199 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -9,8 +9,10 @@ All help in providing PRs to close out bug issues is appreciated. Even if that i
 
 -  UNRELEASED
     - ...
-
-
+-  4.0.2
+    - Fix mock imports as reported in #504 by @llybin. Thank you.
+-  4.0.1 
+    - Fix logo alignment for PyPI 
 -  4.0.0
     - Remove Python2 support (@hugovk)
     - Add Python 3.8 TravisCI support (@neozenith)
diff --git a/tox.ini b/tox.ini
index e73f477..20c4b73 100644
--- a/tox.ini
+++ b/tox.ini
@@ -63,7 +63,6 @@ commands =
     ./runtests.sh --cov=./vcr --cov-branch --cov-report=xml --cov-append {posargs}
 deps =
     Flask
-    mock
     pytest
     pytest-httpbin
     pytest-cov
diff --git a/vcr/__init__.py b/vcr/__init__.py
index 02b6fb1..070d3e9 100644
--- a/vcr/__init__.py
+++ b/vcr/__init__.py
@@ -2,7 +2,7 @@ import logging
 from .config import VCR
 from logging import NullHandler
 
-__version__ = "4.0.1"
+__version__ = "4.0.2"
 
 logging.getLogger(__name__).addHandler(NullHandler())
 
diff --git a/vcr/patch.py b/vcr/patch.py
index 40b462a..3b30407 100644
--- a/vcr/patch.py
+++ b/vcr/patch.py
@@ -2,7 +2,7 @@
 import contextlib
 import functools
 import itertools
-import mock
+from unittest import mock
 
 from .stubs import VCRHTTPConnection, VCRHTTPSConnection
 import http.client as httplib

diff --git a/tests/unit/test_cassettes.py b/tests/unit/test_cassettes.py
index 915f235..90a05c7 100644
--- a/tests/unit/test_cassettes.py
+++ b/tests/unit/test_cassettes.py
@@ -1,13 +1,12 @@
 import contextlib
 import copy
+import http.client as httplib
 import inspect
-import mock
 import os
+from unittest import mock
 
-import http.client as httplib
 import pytest
 import yaml
-
 from vcr.cassette import Cassette
 from vcr.errors import UnhandledHTTPRequestError
 from vcr.patch import force_reset
diff --git a/tests/unit/test_errors.py b/tests/unit/test_errors.py
index fe79253..62c622a 100644
--- a/tests/unit/test_errors.py
+++ b/tests/unit/test_errors.py
@@ -1,4 +1,4 @@
-import mock
+from unittest import mock
 
 import pytest
 
diff --git a/tests/unit/test_filters.py b/tests/unit/test_filters.py
index d40bb0c..69d26bf 100644
--- a/tests/unit/test_filters.py
+++ b/tests/unit/test_filters.py
@@ -11,7 +11,7 @@ from vcr.filters import (
 from vcr.request import Request
 import gzip
 import json
-import mock
+from unittest import mock
 import zlib
 
 
diff --git a/tests/unit/test_matchers.py b/tests/unit/test_matchers.py
index 6c2bd4a..5e45ab6 100644
--- a/tests/unit/test_matchers.py
+++ b/tests/unit/test_matchers.py
@@ -1,5 +1,5 @@
 import itertools
-import mock
+from unittest import mock
 
 import pytest
 
diff --git a/tests/unit/test_serialize.py b/tests/unit/test_serialize.py
index a7efb77..c06d6d3 100644
--- a/tests/unit/test_serialize.py
+++ b/tests/unit/test_serialize.py
@@ -1,5 +1,5 @@
 # -*- encoding: utf-8 -*-
-import mock
+from unittest import mock
 
 import pytest
 
diff --git a/tests/unit/test_stubs.py b/tests/unit/test_stubs.py
index 07d15c1..ee05134 100644
--- a/tests/unit/test_stubs.py
+++ b/tests/unit/test_stubs.py
@@ -1,4 +1,4 @@
-import mock
+from unittest import mock
 
 from vcr.stubs import VCRHTTPSConnection
 from vcr.cassette import Cassette
diff --git a/tests/unit/test_vcr.py b/tests/unit/test_vcr.py
index 49e9000..c49a4b9 100644
--- a/tests/unit/test_vcr.py
+++ b/tests/unit/test_vcr.py
@@ -1,4 +1,4 @@
-import mock
+from unittest import mock
 import os
 
 import pytest

python 3.8 vcrpy 4.0.1 No module named 'mock'
```
python3.8/site-packages/vcr/patch.py", line 5, in <module>
    import mock
ModuleNotFoundError: No module named 'mock'
```

my suggestion: everywhere in projects change:

import mock -> from unittest import mock
tests/unit/test_cassettes.py::test_cassette_load tests/unit/test_cassettes.py::test_cassette_not_played tests/unit/test_cassettes.py::test_cassette_append tests/unit/test_cassettes.py::test_cassette_len tests/unit/test_cassettes.py::test_cassette_contains tests/unit/test_cassettes.py::test_cassette_responses_of tests/unit/test_cassettes.py::test_cassette_get_missing_response tests/unit/test_cassettes.py::test_cassette_cant_read_same_request_twice tests/unit/test_cassettes.py::test_function_decorated_with_use_cassette_can_be_invoked_multiple_times tests/unit/test_cassettes.py::test_arg_getter_functionality tests/unit/test_cassettes.py::test_cassette_not_all_played tests/unit/test_cassettes.py::test_cassette_all_played tests/unit/test_cassettes.py::test_cassette_rewound tests/unit/test_cassettes.py::test_before_record_response tests/unit/test_cassettes.py::test_nesting_cassette_context_managers tests/unit/test_cassettes.py::test_nesting_context_managers_by_checking_references_of_http_connection tests/unit/test_cassettes.py::test_custom_patchers tests/unit/test_cassettes.py::test_decorated_functions_are_reentrant tests/unit/test_cassettes.py::test_cassette_use_called_without_path_uses_function_to_generate_path tests/unit/test_cassettes.py::test_path_transformer_with_function_path tests/unit/test_cassettes.py::test_path_transformer_with_context_manager tests/unit/test_cassettes.py::test_path_transformer_None tests/unit/test_cassettes.py::test_func_path_generator tests/unit/test_cassettes.py::test_use_as_decorator_on_coroutine tests/unit/test_cassettes.py::test_use_as_decorator_on_generator tests/unit/test_cassettes.py::test_find_requests_with_most_matches_one_similar_request tests/unit/test_cassettes.py::test_find_requests_with_most_matches_no_similar_requests tests/unit/test_cassettes.py::test_find_requests_with_most_matches_many_similar_requests tests/unit/test_errors.py::test_CannotOverwriteExistingCassetteException_get_message[most_matches0-No tests/unit/test_errors.py::test_CannotOverwriteExistingCassetteException_get_message[most_matches1-Found tests/unit/test_errors.py::test_CannotOverwriteExistingCassetteException_get_message[most_matches2-Found tests/unit/test_errors.py::test_CannotOverwriteExistingCassetteException_get_message[most_matches3-Found tests/unit/test_filters.py::test_replace_headers tests/unit/test_filters.py::test_replace_headers_empty tests/unit/test_filters.py::test_replace_headers_callable tests/unit/test_filters.py::test_remove_headers tests/unit/test_filters.py::test_replace_query_parameters tests/unit/test_filters.py::test_remove_all_query_parameters tests/unit/test_filters.py::test_replace_query_parameters_callable tests/unit/test_filters.py::test_remove_query_parameters tests/unit/test_filters.py::test_replace_post_data_parameters tests/unit/test_filters.py::test_replace_post_data_parameters_empty_body tests/unit/test_filters.py::test_remove_post_data_parameters tests/unit/test_filters.py::test_preserve_multiple_post_data_parameters tests/unit/test_filters.py::test_remove_all_post_data_parameters tests/unit/test_filters.py::test_replace_json_post_data_parameters tests/unit/test_filters.py::test_remove_json_post_data_parameters tests/unit/test_filters.py::test_remove_all_json_post_data_parameters tests/unit/test_filters.py::test_decode_response_uncompressed tests/unit/test_filters.py::test_decode_response_deflate tests/unit/test_filters.py::test_decode_response_gzip tests/unit/test_matchers.py::test_uri_matcher tests/unit/test_matchers.py::test_body_matcher_does_match[r10-r20] tests/unit/test_matchers.py::test_body_matcher_does_match[r11-r21] tests/unit/test_matchers.py::test_body_matcher_does_match[r12-r22] tests/unit/test_matchers.py::test_body_matcher_does_match[r13-r23] tests/unit/test_matchers.py::test_body_matcher_does_match[r14-r24] tests/unit/test_matchers.py::test_body_matcher_does_match[r15-r25] tests/unit/test_matchers.py::test_body_matcher_does_match[r16-r26] tests/unit/test_matchers.py::test_body_matcher_does_match[r17-r27] tests/unit/test_matchers.py::test_body_match_does_not_match[r10-r20] tests/unit/test_matchers.py::test_body_match_does_not_match[r11-r21] tests/unit/test_matchers.py::test_body_match_does_not_match[r12-r22] tests/unit/test_matchers.py::test_query_matcher tests/unit/test_matchers.py::test_matchers tests/unit/test_matchers.py::test_evaluate_matcher_does_match tests/unit/test_matchers.py::test_evaluate_matcher_does_not_match tests/unit/test_matchers.py::test_evaluate_matcher_does_not_match_with_assert_message tests/unit/test_matchers.py::test_get_assertion_message tests/unit/test_matchers.py::test_get_assertion_message_with_details tests/unit/test_matchers.py::test_get_matchers_results[r10-r20-expected_successes0-expected_failures0] tests/unit/test_matchers.py::test_get_matchers_results[r11-r21-expected_successes1-expected_failures1] tests/unit/test_matchers.py::test_get_matchers_results[r12-r22-expected_successes2-expected_failures2] tests/unit/test_matchers.py::test_requests_match[successes0-failures0-True] tests/unit/test_matchers.py::test_requests_match[successes1-failures1-False] tests/unit/test_matchers.py::test_requests_match[successes2-failures2-False] tests/unit/test_serialize.py::test_deserialize_old_yaml_cassette tests/unit/test_serialize.py::test_deserialize_old_json_cassette tests/unit/test_serialize.py::test_deserialize_new_yaml_cassette tests/unit/test_serialize.py::test_deserialize_new_json_cassette tests/unit/test_serialize.py::test_deserialize_py2py3_yaml_cassette[x=5&y=2-x=5&y=2] tests/unit/test_serialize.py::test_deserialize_py2py3_yaml_cassette[!!binary tests/unit/test_serialize.py::test_deserialize_py2py3_yaml_cassette[!!python/str tests/unit/test_serialize.py::test_serialize_constructs_UnicodeDecodeError tests/unit/test_serialize.py::test_serialize_empty_request tests/unit/test_serialize.py::test_serialize_json_request tests/unit/test_serialize.py::test_serialize_binary_request tests/unit/test_serialize.py::test_deserialize_no_body_string tests/unit/test_stubs.py::TestVCRConnection::test_setting_of_attributes_get_propogated_to_real_connection tests/unit/test_stubs.py::TestVCRConnection::testing_connect tests/unit/test_vcr.py::test_vcr_use_cassette tests/unit/test_vcr.py::test_vcr_before_record_request_params tests/unit/test_vcr.py::test_vcr_before_record_response_iterable tests/unit/test_vcr.py::test_before_record_response_as_filter tests/unit/test_vcr.py::test_vcr_path_transformer tests/unit/test_vcr.py::test_fixtures_with_use_cassette tests/unit/test_vcr.py::test_custom_patchers tests/unit/test_vcr.py::test_inject_cassette tests/unit/test_vcr.py::test_with_current_defaults tests/unit/test_vcr.py::test_cassette_library_dir_with_decoration_and_no_explicit_path tests/unit/test_vcr.py::test_cassette_library_dir_with_decoration_and_explicit_path tests/unit/test_vcr.py::test_cassette_library_dir_with_decoration_and_super_explicit_path tests/unit/test_vcr.py::test_cassette_library_dir_with_path_transformer tests/unit/test_vcr.py::test_use_cassette_with_no_extra_invocation tests/unit/test_vcr.py::test_path_transformer tests/unit/test_vcr.py::test_cassette_name_generator_defaults_to_using_module_function_defined_in tests/unit/test_vcr.py::test_ensure_suffix tests/unit/test_vcr.py::test_additional_matchers tests/unit/test_vcr.py::test_decoration_should_respect_function_return_value tests/unit/test_vcr.py::TestVCRClass::test_one tests/unit/test_vcr.py::TestVCRClass::test_two tests/unit/test_vcr.py::TestVCRClass::test_dynamically_added