diff --git a/poetry.lock b/poetry.lock
index 06f021d..5c9c35a 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1053,19 +1053,20 @@ python-versions = "*"
 
 [[package]]
 name = "sphinx"
-version = "3.5.4"
+version = "4.0.0"
 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,<0.17"
+docutils = ">=0.14,<0.18"
 imagesize = "*"
-Jinja2 = ">=2.3"
+Jinja2 = ">=2.3,<3.0"
+MarkupSafe = "<2.0"
 packaging = "*"
 Pygments = ">=2.0"
 requests = ">=2.5.0"
@@ -1319,7 +1320,7 @@ testing = ["pathlib2", "contextlib2", "unittest2"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.6"
-content-hash = "eb10299c34d11bd3f9a22f9c523e08116c9949084ffd92367df44abd55f4505d"
+content-hash = "97cc289930c2aaef9f7b0d7763a026c8f53bffd9092537041f9ecf49a6968e4c"
 
 [metadata.files]
 aiocontextvars = [
@@ -1882,8 +1883,8 @@ sortedcontainers = [
     {file = "sortedcontainers-2.1.0.tar.gz", hash = "sha256:974e9a32f56b17c1bac2aebd9dcf197f3eb9cd30553c5852a3187ad162e1a03a"},
 ]
 sphinx = [
-    {file = "Sphinx-3.5.4-py3-none-any.whl", hash = "sha256:2320d4e994a191f4b4be27da514e46b3d6b420f2ff895d064f52415d342461e8"},
-    {file = "Sphinx-3.5.4.tar.gz", hash = "sha256:19010b7b9fa0dc7756a6e105b2aacd3a80f798af3c25c273be64d7beeb482cb1"},
+    {file = "Sphinx-4.0.0-py3-none-any.whl", hash = "sha256:904e02cd0f84bed5d3748358c228ae3df3ad725b9e6cdc2166e17b309ed2e1fa"},
+    {file = "Sphinx-4.0.0.tar.gz", hash = "sha256:b246ebd74f5fb966d7e90086bbda5ed74ee4d30b4c3cbefddc1fb5210aa317c7"},
 ]
 sphinx-autodoc-typehints = [
     {file = "sphinx-autodoc-typehints-1.12.0.tar.gz", hash = "sha256:193617d9dbe0847281b1399d369e74e34cd959c82e02c7efde077fca908a9f52"},
diff --git a/pyproject.toml b/pyproject.toml
index 0772f76..7ecfa59 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -60,7 +60,7 @@ pytest-cov = "^2.11"
 pytest-randomly = "^3.7"
 pytest-mypy-plugins = "^1.6"
 
-sphinx = "^3.5"
+sphinx = "^4.0"
 sphinx-autodoc-typehints = "^1.12"
 sphinxcontrib-mermaid = "^0.6.3"
 sphinx-typlog-theme = "^0.8.0"