diff --git a/poetry.lock b/poetry.lock
index 03f591c..33d0a03 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -211,17 +211,17 @@ testing = ["covdefaults (>=1.2.0)", "coverage (>=4)", "pytest (>=4)", "pytest-co
 
 [[package]]
 name = "flake8"
-version = "3.9.2"
+version = "4.0.1"
 description = "the modular source code checker: pep8 pyflakes and co"
 category = "dev"
 optional = false
-python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.7"
+python-versions = ">=3.6"
 
 [package.dependencies]
-importlib-metadata = {version = "*", markers = "python_version < \"3.8\""}
+importlib-metadata = {version = "<4.3", markers = "python_version < \"3.8\""}
 mccabe = ">=0.6.0,<0.7.0"
-pycodestyle = ">=2.7.0,<2.8.0"
-pyflakes = ">=2.3.0,<2.4.0"
+pycodestyle = ">=2.8.0,<2.9.0"
+pyflakes = ">=2.4.0,<2.5.0"
 
 [[package]]
 name = "google-api-core"
@@ -338,7 +338,7 @@ python-versions = ">=3.5"
 
 [[package]]
 name = "importlib-metadata"
-version = "4.8.2"
+version = "4.2.0"
 description = "Read metadata from Python packages"
 category = "main"
 optional = false
@@ -350,8 +350,7 @@ zipp = ">=0.5"
 
 [package.extras]
 docs = ["sphinx", "jaraco.packaging (>=8.2)", "rst.linker (>=1.9)"]
-perf = ["ipython"]
-testing = ["pytest (>=6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytest-cov", "pytest-enabler (>=1.0.1)", "packaging", "pep517", "pyfakefs", "flufl.flake8", "pytest-perf (>=0.9.2)", "pytest-black (>=0.3.7)", "pytest-mypy", "importlib-resources (>=1.3)"]
+testing = ["pytest (>=4.6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytest-cov", "pytest-enabler (>=1.0.1)", "packaging", "pep517", "pyfakefs", "flufl.flake8", "pytest-black (>=0.3.7)", "pytest-mypy", "importlib-resources (>=1.3)"]
 
 [[package]]
 name = "importlib-resources"
@@ -616,11 +615,11 @@ pyasn1 = ">=0.4.6,<0.5.0"
 
 [[package]]
 name = "pycodestyle"
-version = "2.7.0"
+version = "2.8.0"
 description = "Python style guide checker"
 category = "dev"
 optional = false
-python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
 
 [[package]]
 name = "pycparser"
@@ -646,7 +645,7 @@ toml = ["toml"]
 
 [[package]]
 name = "pyflakes"
-version = "2.3.1"
+version = "2.4.0"
 description = "passive checker of Python programs"
 category = "dev"
 optional = false
@@ -964,7 +963,7 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytes
 [metadata]
 lock-version = "1.1"
 python-versions = "<3.10,>=3.6.2"
-content-hash = "ffacd413f9d027f39bdd6048adfde97061432d5bad9a127deac7c95f2b543fa0"
+content-hash = "00d92d39dd1b23636918c724f857171fd2456dadfa0e3482022314b9f8b2e225"
 
 [metadata.files]
 atomicwrites = [
@@ -1153,8 +1152,8 @@ filelock = [
     {file = "filelock-3.4.0.tar.gz", hash = "sha256:93d512b32a23baf4cac44ffd72ccf70732aeff7b8050fcaf6d3ec406d954baf4"},
 ]
 flake8 = [
-    {file = "flake8-3.9.2-py2.py3-none-any.whl", hash = "sha256:bf8fd333346d844f616e8d47905ef3a3384edae6b4e9beb0c5101e25e3110907"},
-    {file = "flake8-3.9.2.tar.gz", hash = "sha256:07528381786f2a6237b061f6e96610a4167b226cb926e2aa2b6b1d78057c576b"},
+    {file = "flake8-4.0.1-py2.py3-none-any.whl", hash = "sha256:479b1304f72536a55948cb40a32dce8bb0ffe3501e26eaf292c7e60eb5e0428d"},
+    {file = "flake8-4.0.1.tar.gz", hash = "sha256:806e034dda44114815e23c16ef92f95c91e4c71100ff52813adf7132a6ad870d"},
 ]
 google-api-core = [
     {file = "google-api-core-1.31.4.tar.gz", hash = "sha256:c77ffc8b4981b44efdb9d68431fd96d21dbd39545c29552bbe79b9b7dd2c3689"},
@@ -1242,8 +1241,8 @@ idna = [
     {file = "idna-3.3.tar.gz", hash = "sha256:9d643ff0a55b762d5cdb124b8eaa99c66322e2157b69160bc32796e824360e6d"},
 ]
 importlib-metadata = [
-    {file = "importlib_metadata-4.8.2-py3-none-any.whl", hash = "sha256:53ccfd5c134223e497627b9815d5030edf77d2ed573922f7a0b8f8bb81a1c100"},
-    {file = "importlib_metadata-4.8.2.tar.gz", hash = "sha256:75bdec14c397f528724c1bfd9709d660b33a4d2e77387a3358f20b848bb5e5fb"},
+    {file = "importlib_metadata-4.2.0-py3-none-any.whl", hash = "sha256:057e92c15bc8d9e8109738a48db0ccb31b4d9d5cfbee5a8670879a30be66304b"},
+    {file = "importlib_metadata-4.2.0.tar.gz", hash = "sha256:b7e52a1f8dec14a75ea73e0891f3060099ca1d8e6a462a4dff11c3e119ea1b31"},
 ]
 importlib-resources = [
     {file = "importlib_resources-5.4.0-py3-none-any.whl", hash = "sha256:33a95faed5fc19b4bc16b29a6eeae248a3fe69dd55d4d229d2b480e23eeaad45"},
@@ -1423,8 +1422,8 @@ pyasn1-modules = [
     {file = "pyasn1_modules-0.2.8-py3.7.egg", hash = "sha256:c29a5e5cc7a3f05926aff34e097e84f8589cd790ce0ed41b67aed6857b26aafd"},
 ]
 pycodestyle = [
-    {file = "pycodestyle-2.7.0-py2.py3-none-any.whl", hash = "sha256:514f76d918fcc0b55c6680472f0a37970994e07bbb80725808c17089be302068"},
-    {file = "pycodestyle-2.7.0.tar.gz", hash = "sha256:c389c1d06bf7904078ca03399a4816f974a1d590090fecea0c63ec26ebaf1cef"},
+    {file = "pycodestyle-2.8.0-py2.py3-none-any.whl", hash = "sha256:720f8b39dde8b293825e7ff02c475f3077124006db4f440dcbc9a20b76548a20"},
+    {file = "pycodestyle-2.8.0.tar.gz", hash = "sha256:eddd5847ef438ea1c7870ca7eb78a9d47ce0cdb4851a5523949f2601d0cbbe7f"},
 ]
 pycparser = [
     {file = "pycparser-2.21-py2.py3-none-any.whl", hash = "sha256:8ee45429555515e1f6b185e78100aea234072576aa43ab53aefcae078162fca9"},
@@ -1435,8 +1434,8 @@ pydocstyle = [
     {file = "pydocstyle-6.1.1.tar.gz", hash = "sha256:1d41b7c459ba0ee6c345f2eb9ae827cab14a7533a88c5c6f7e94923f72df92dc"},
 ]
 pyflakes = [
-    {file = "pyflakes-2.3.1-py2.py3-none-any.whl", hash = "sha256:7893783d01b8a89811dd72d7dfd4d84ff098e5eed95cfa8905b22bbffe52efc3"},
-    {file = "pyflakes-2.3.1.tar.gz", hash = "sha256:f5bc8ecabc05bb9d291eb5203d6810b49040f6ff446a756326104746cc00c1db"},
+    {file = "pyflakes-2.4.0-py2.py3-none-any.whl", hash = "sha256:3bb3a3f256f4b7968c9c788781e4ff07dce46bdf12339dcda61053375426ee2e"},
+    {file = "pyflakes-2.4.0.tar.gz", hash = "sha256:05a85c2872edf37a4ed30b0cce2f6093e1d0581f8c19d7393122da7e25b2b24c"},
 ]
 pyjwt = [
     {file = "PyJWT-1.7.1-py2.py3-none-any.whl", hash = "sha256:5c6eca3c2940464d106b99ba83b00c6add741c9becaec087fb7ccdefea71350e"},
diff --git a/pyproject.toml b/pyproject.toml
index bf8f2a9..4ae7c23 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ oauth2client = "4.1.3"
 [tool.poetry.dev-dependencies]
 pytest = "^6.2.5"
 tox = "^3.24.5"
-flake8 = "^3.9.2"
+flake8 = "^4.0.1"
 black = "^21.9b0"
 pydocstyle = "^6.1.1"
 mypy = "^0.910"