diff --git a/poetry.lock b/poetry.lock
index aca1089c..71738d0b 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -870,7 +870,7 @@ python-versions = "*"
 
 [[package]]
 name = "sphinx"
-version = "4.0.2"
+version = "4.1.1"
 description = "Python documentation generator"
 category = "dev"
 optional = false
@@ -889,14 +889,14 @@ requests = ">=2.5.0"
 snowballstemmer = ">=1.1"
 sphinxcontrib-applehelp = "*"
 sphinxcontrib-devhelp = "*"
-sphinxcontrib-htmlhelp = "*"
+sphinxcontrib-htmlhelp = ">=2.0.0"
 sphinxcontrib-jsmath = "*"
 sphinxcontrib-qthelp = "*"
-sphinxcontrib-serializinghtml = "*"
+sphinxcontrib-serializinghtml = ">=1.1.5"
 
 [package.extras]
 docs = ["sphinxcontrib-websupport"]
-lint = ["flake8 (>=3.5.0)", "isort", "mypy (>=0.800)", "docutils-stubs"]
+lint = ["flake8 (>=3.5.0)", "isort", "mypy (>=0.900)", "docutils-stubs", "types-typed-ast", "types-pkg-resources", "types-requests"]
 test = ["pytest", "pytest-cov", "html5lib", "cython", "typed-ast"]
 
 [[package]]
@@ -969,11 +969,11 @@ test = ["pytest"]
 
 [[package]]
 name = "sphinxcontrib-htmlhelp"
-version = "1.0.3"
+version = "2.0.0"
 description = "sphinxcontrib-htmlhelp is a sphinx extension which renders HTML help files"
 category = "dev"
 optional = false
-python-versions = ">=3.5"
+python-versions = ">=3.6"
 
 [package.extras]
 lint = ["flake8", "mypy", "docutils-stubs"]
@@ -1004,7 +1004,7 @@ test = ["pytest"]
 
 [[package]]
 name = "sphinxcontrib-serializinghtml"
-version = "1.1.4"
+version = "1.1.5"
 description = "sphinxcontrib-serializinghtml is a sphinx extension which outputs \"serialized\" HTML files (json and pickle)."
 category = "dev"
 optional = false
@@ -1187,7 +1187,7 @@ cli = ["click", "tabulate", "dateparser"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7.1"
-content-hash = "d186d7bd33b63795d268d60390940b3f562c548d1abc57900ef32018f41c74c0"
+content-hash = "63dd54438549c046019ad6a2c556c306899263f2d8954ff4b2487fe13c6b8ba7"
 
 [metadata.files]
 aiohttp = [
@@ -1773,8 +1773,8 @@ snowballstemmer = [
     {file = "snowballstemmer-2.0.0.tar.gz", hash = "sha256:df3bac3df4c2c01363f3dd2cfa78cce2840a79b9f1c2d2de9ce8d31683992f52"},
 ]
 sphinx = [
-    {file = "Sphinx-4.0.2-py3-none-any.whl", hash = "sha256:d1cb10bee9c4231f1700ec2e24a91be3f3a3aba066ea4ca9f3bbe47e59d5a1d4"},
-    {file = "Sphinx-4.0.2.tar.gz", hash = "sha256:b5c2ae4120bf00c799ba9b3699bc895816d272d120080fbc967292f29b52b48c"},
+    {file = "Sphinx-4.1.1-py3-none-any.whl", hash = "sha256:3d513088236eef51e5b0adb78b0492eb22cc3b8ccdb0b36dd021173b365d4454"},
+    {file = "Sphinx-4.1.1.tar.gz", hash = "sha256:23c846a1841af998cb736218539bb86d16f5eb95f5760b1966abcd2d584e62b8"},
 ]
 sphinx-autobuild = [
     {file = "sphinx-autobuild-2021.3.14.tar.gz", hash = "sha256:de1ca3b66e271d2b5b5140c35034c89e47f263f2cd5db302c9217065f7443f05"},
@@ -1797,8 +1797,8 @@ sphinxcontrib-devhelp = [
     {file = "sphinxcontrib_devhelp-1.0.2-py2.py3-none-any.whl", hash = "sha256:8165223f9a335cc1af7ffe1ed31d2871f325254c0423bc0c4c7cd1c1e4734a2e"},
 ]
 sphinxcontrib-htmlhelp = [
-    {file = "sphinxcontrib-htmlhelp-1.0.3.tar.gz", hash = "sha256:e8f5bb7e31b2dbb25b9cc435c8ab7a79787ebf7f906155729338f3156d93659b"},
-    {file = "sphinxcontrib_htmlhelp-1.0.3-py2.py3-none-any.whl", hash = "sha256:3c0bc24a2c41e340ac37c85ced6dafc879ab485c095b1d65d2461ac2f7cca86f"},
+    {file = "sphinxcontrib-htmlhelp-2.0.0.tar.gz", hash = "sha256:f5f8bb2d0d629f398bf47d0d69c07bc13b65f75a81ad9e2f71a63d4b7a2f6db2"},
+    {file = "sphinxcontrib_htmlhelp-2.0.0-py2.py3-none-any.whl", hash = "sha256:d412243dfb797ae3ec2b59eca0e52dac12e75a241bf0e4eb861e450d06c6ed07"},
 ]
 sphinxcontrib-jsmath = [
     {file = "sphinxcontrib-jsmath-1.0.1.tar.gz", hash = "sha256:a9925e4a4587247ed2191a22df5f6970656cb8ca2bd6284309578f2153e0c4b8"},
@@ -1809,8 +1809,8 @@ sphinxcontrib-qthelp = [
     {file = "sphinxcontrib_qthelp-1.0.3-py2.py3-none-any.whl", hash = "sha256:bd9fc24bcb748a8d51fd4ecaade681350aa63009a347a8c14e637895444dfab6"},
 ]
 sphinxcontrib-serializinghtml = [
-    {file = "sphinxcontrib-serializinghtml-1.1.4.tar.gz", hash = "sha256:eaa0eccc86e982a9b939b2b82d12cc5d013385ba5eadcc7e4fed23f4405f77bc"},
-    {file = "sphinxcontrib_serializinghtml-1.1.4-py2.py3-none-any.whl", hash = "sha256:f242a81d423f59617a8e5cf16f5d4d74e28ee9a66f9e5b637a18082991db5a9a"},
+    {file = "sphinxcontrib-serializinghtml-1.1.5.tar.gz", hash = "sha256:aa5f6de5dfdf809ef505c4895e51ef5c9eac17d0f287933eb49ec495280b6952"},
+    {file = "sphinxcontrib_serializinghtml-1.1.5-py2.py3-none-any.whl", hash = "sha256:352a9a00ae864471d3a7ead8d7d79f5fc0b57e8b3f95e9867eb9eb28999b92fd"},
 ]
 stevedore = [
     {file = "stevedore-3.3.0-py3-none-any.whl", hash = "sha256:50d7b78fbaf0d04cd62411188fa7eedcb03eb7f4c4b37005615ceebe582aa82a"},
diff --git a/pyproject.toml b/pyproject.toml
index 60d59eba..8e1c12bb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,7 @@ safety = "^1.10.3"
 mypy = "^0.812"
 typeguard = "^2.12.1"
 xdoctest = {extras = ["colors"], version = "^0.15.5"}
-sphinx = "^4.0.2"
+sphinx = "^4.1.1"
 sphinx-autobuild = "^2021.3.14"
 pre-commit = "^2.13.0"
 flake8 = "^3.9.2"