diff --git a/poetry.lock b/poetry.lock
index 9a6ea94..a3ed712 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1060,17 +1060,17 @@ python-versions = ">=3.6"
 
 [[package]]
 name = "sphinx"
-version = "3.5.2"
+version = "4.3.2"
 description = "Python documentation generator"
 category = "dev"
 optional = false
-python-versions = ">=3.5"
+python-versions = ">=3.6"
 
 [package.dependencies]
 alabaster = ">=0.7,<0.8"
 babel = ">=1.3"
 colorama = {version = ">=0.3.5", markers = "sys_platform == \"win32\""}
-docutils = ">=0.12"
+docutils = ">=0.14,<0.18"
 imagesize = "*"
 Jinja2 = ">=2.3"
 packaging = "*"
@@ -1079,14 +1079,14 @@ 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 (>=0.920)", "docutils-stubs", "types-typed-ast", "types-pkg-resources", "types-requests"]
 test = ["pytest", "pytest-cov", "html5lib", "cython", "typed-ast"]
 
 [[package]]
@@ -1130,11 +1130,11 @@ 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"]
@@ -1165,7 +1165,7 @@ 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
@@ -1351,7 +1351,7 @@ python-versions = "*"
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.9"
-content-hash = "1a8e7e4fb91b4058d8e3c6292b092fd50f7963fea646172c45bcfe4749ef4b6c"
+content-hash = "70237620ffc4dda4f30285ade9df69902a8092a2d5b6b35c86a9bb10c1aad85c"
 
 [metadata.files]
 alabaster = [
@@ -1934,8 +1934,8 @@ soupsieve = [
     {file = "soupsieve-2.2.tar.gz", hash = "sha256:407fa1e8eb3458d1b5614df51d9651a1180ea5fedf07feb46e45d7e25e6d6cdd"},
 ]
 sphinx = [
-    {file = "Sphinx-3.5.2-py3-none-any.whl", hash = "sha256:ef64a814576f46ec7de06adf11b433a0d6049be007fefe7fd0d183d28b581fac"},
-    {file = "Sphinx-3.5.2.tar.gz", hash = "sha256:672cfcc24b6b69235c97c750cb190a44ecd72696b4452acaf75c2d9cc78ca5ff"},
+    {file = "Sphinx-4.3.2-py3-none-any.whl", hash = "sha256:6a11ea5dd0bdb197f9c2abc2e0ce73e01340464feaece525e64036546d24c851"},
+    {file = "Sphinx-4.3.2.tar.gz", hash = "sha256:0a8836751a68306b3fe97ecbe44db786f8479c3bf4b80e3a7f5c838657b4698c"},
 ]
 sphinx-autodoc-typehints = [
     {file = "sphinx-autodoc-typehints-1.11.1.tar.gz", hash = "sha256:244ba6d3e2fdb854622f643c7763d6f95b6886eba24bec28e86edf205e4ddb20"},
@@ -1950,8 +1950,8 @@ 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"},
@@ -1962,8 +1962,8 @@ 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 b433f89..adf950b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -61,7 +61,7 @@ pytest-cov = "^2.10"
 pytest-randomly = "^3.4"
 coverage = "^5.5"
 
-sphinx = "^3.5"
+sphinx = "^4.3"
 sphinx-autodoc-typehints = "^1.11"
 
 doc8 = "^0.8"