diff --git a/poetry.lock b/poetry.lock
index 4e3e209..b54569a 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -127,17 +127,17 @@ python-versions = "*"
 
 [[package]]
 name = "flake8"
-version = "3.9.1"
+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 = "gitdb"
@@ -334,15 +334,15 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 
 [[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 = "pyflakes"
-version = "2.3.1"
+version = "2.4.0"
 description = "passive checker of Python programs"
 category = "dev"
 optional = false
@@ -519,7 +519,7 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pyt
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.6.1"
-content-hash = "74c1372394b150f7633c31f62c841e1f2e0fec8ae94493fc84550859fa019e25"
+content-hash = "e7227d4f725fc0ba0d46dd4fe03ce01713aeb7fbea1944d2c2d59442e6a99b0d"
 
 [metadata.files]
 appdirs = [
@@ -620,8 +620,8 @@ filelock = [
     {file = "filelock-3.0.12.tar.gz", hash = "sha256:18d82244ee114f543149c66a6e0c14e9c4f8a1044b5cdaadd0f82159d6a6ff59"},
 ]
 flake8 = [
-    {file = "flake8-3.9.1-py2.py3-none-any.whl", hash = "sha256:3b9f848952dddccf635be78098ca75010f073bfe14d2c6bda867154bea728d2a"},
-    {file = "flake8-3.9.1.tar.gz", hash = "sha256:1aa8990be1e689d96c745c5682b687ea49f2e05a443aff1f8251092b0014e378"},
+    {file = "flake8-4.0.1-py2.py3-none-any.whl", hash = "sha256:479b1304f72536a55948cb40a32dce8bb0ffe3501e26eaf292c7e60eb5e0428d"},
+    {file = "flake8-4.0.1.tar.gz", hash = "sha256:806e034dda44114815e23c16ef92f95c91e4c71100ff52813adf7132a6ad870d"},
 ]
 gitdb = [
     {file = "gitdb-4.0.7-py3-none-any.whl", hash = "sha256:6c4cc71933456991da20917998acbe6cf4fb41eeaab7d6d67fbc05ecd4c865b0"},
@@ -712,12 +712,12 @@ py = [
     {file = "py-1.10.0.tar.gz", hash = "sha256:21b81bda15b66ef5e1a777a21c4dcd9c20ad3efd0b3f817e7a809035269e1bd3"},
 ]
 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"},
 ]
 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"},
 ]
 pyparsing = [
     {file = "pyparsing-2.4.7-py2.py3-none-any.whl", hash = "sha256:ef9d7589ef3c200abe66653d3f1ab1033c3c419ae9b9bdb1240a85b024efc88b"},
diff --git a/pyproject.toml b/pyproject.toml
index e0910ce..a543ac8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ python = "^3.6.1"
 bandit = "^1.7.0"
 pytest-cov = "^2.11.1"
 pre-commit = "^2.12.1"
-flake8 = "^3.9.1"
+flake8 = "^4.0.1"
 tox = "^3.23.0"
 pytest = "^6.2.3"
 mypy = "^0.812"