diff --git a/poetry.lock b/poetry.lock
index 26f38983..fae2ca82 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -711,7 +711,7 @@ python-versions = "*"
 
 [[package]]
 name = "sphinx"
-version = "3.5.2"
+version = "3.5.3"
 description = "Python documentation generator"
 category = "dev"
 optional = false
@@ -964,7 +964,7 @@ testing = ["pytest (>=3.5,!=3.7.3)", "pytest-checkdocs (>=1.2.3)", "pytest-flake
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7.0"
-content-hash = "39c877bf676f15899a948cf40e0bd3df23c932ddb5b645c7386f660bf85d15ca"
+content-hash = "49dab781c4c71377ea417ccac92e11a3cceddb18db76522b33e98055f29c0176"
 
 [metadata.files]
 alabaster = [
@@ -1428,8 +1428,8 @@ snowballstemmer = [
     {file = "snowballstemmer-2.0.0.tar.gz", hash = "sha256:df3bac3df4c2c01363f3dd2cfa78cce2840a79b9f1c2d2de9ce8d31683992f52"},
 ]
 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-3.5.3-py3-none-any.whl", hash = "sha256:3f01732296465648da43dec8fb40dc451ba79eb3e2cc5c6d79005fd98197107d"},
+    {file = "Sphinx-3.5.3.tar.gz", hash = "sha256:ce9c228456131bab09a3d7d10ae58474de562a6f79abb3dc811ae401cf8c1abc"},
 ]
 sphinx-autobuild = [
     {file = "sphinx-autobuild-2021.3.14.tar.gz", hash = "sha256:de1ca3b66e271d2b5b5140c35034c89e47f263f2cd5db302c9217065f7443f05"},
diff --git a/pyproject.toml b/pyproject.toml
index 6e1358a5..200c9117 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ safety = "^1.10.3"
 mypy = "^0.812"
 typeguard = "^2.11.1"
 xdoctest = {extras = ["colors"], version = "^0.15.0"}
-sphinx = "^3.5.2"
+sphinx = "^3.5.3"
 sphinx-autobuild = "^2021.3.14"
 pre-commit = "^2.11.1"
 flake8 = "^3.9.0"