diff --git a/CHANGELOG.md b/CHANGELOG.md
index d0366ec..1d63474 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 
 ## [Unreleased]
+### Changed
+- Upgrade dev dependencies.
 
 ## [0.1.0] - 2024-08-03
 ### Added
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 165c943..ce49af9 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,2 +1,2 @@
-sphinx==7.2.6
+sphinx==8.0.2
 recommonmark==0.7.1
diff --git a/poetry.lock b/poetry.lock
index 30ab0d1..15a728f 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.2 and should not be changed by hand.
 
 [[package]]
 name = "alabaster"
@@ -2868,26 +2868,26 @@ files = [
 
 [[package]]
 name = "sphinx"
-version = "7.3.7"
+version = "8.0.2"
 description = "Python documentation generator"
 optional = false
-python-versions = ">=3.9"
+python-versions = ">=3.10"
 files = [
-    {file = "sphinx-7.3.7-py3-none-any.whl", hash = "sha256:413f75440be4cacf328f580b4274ada4565fb2187d696a84970c23f77b64d8c3"},
-    {file = "sphinx-7.3.7.tar.gz", hash = "sha256:a4a7db75ed37531c05002d56ed6948d4c42f473a36f46e1382b0bd76ca9627bc"},
+    {file = "sphinx-8.0.2-py3-none-any.whl", hash = "sha256:56173572ae6c1b9a38911786e206a110c9749116745873feae4f9ce88e59391d"},
+    {file = "sphinx-8.0.2.tar.gz", hash = "sha256:0cce1ddcc4fd3532cf1dd283bc7d886758362c5c1de6598696579ce96d8ffa5b"},
 ]
 
 [package.dependencies]
-alabaster = ">=0.7.14,<0.8.0"
-babel = ">=2.9"
-colorama = {version = ">=0.4.5", markers = "sys_platform == \"win32\""}
-docutils = ">=0.18.1,<0.22"
+alabaster = ">=0.7.14"
+babel = ">=2.13"
+colorama = {version = ">=0.4.6", markers = "sys_platform == \"win32\""}
+docutils = ">=0.20,<0.22"
 imagesize = ">=1.3"
-Jinja2 = ">=3.0"
-packaging = ">=21.0"
-Pygments = ">=2.14"
-requests = ">=2.25.0"
-snowballstemmer = ">=2.0"
+Jinja2 = ">=3.1"
+packaging = ">=23.0"
+Pygments = ">=2.17"
+requests = ">=2.30.0"
+snowballstemmer = ">=2.2"
 sphinxcontrib-applehelp = "*"
 sphinxcontrib-devhelp = "*"
 sphinxcontrib-htmlhelp = ">=2.0.0"
@@ -2898,8 +2898,8 @@ tomli = {version = ">=2", markers = "python_version < \"3.11\""}
 
 [package.extras]
 docs = ["sphinxcontrib-websupport"]
-lint = ["flake8 (>=3.5.0)", "importlib_metadata", "mypy (==1.9.0)", "pytest (>=6.0)", "ruff (==0.3.7)", "sphinx-lint", "tomli", "types-docutils", "types-requests"]
-test = ["cython (>=3.0)", "defusedxml (>=0.7.1)", "pytest (>=6.0)", "setuptools (>=67.0)"]
+lint = ["flake8 (>=6.0)", "mypy (==1.11.0)", "pytest (>=6.0)", "ruff (==0.5.5)", "sphinx-lint (>=0.9)", "tomli (>=2)", "types-Pillow (==10.2.0.20240520)", "types-Pygments (==2.18.0.20240506)", "types-colorama (==0.4.15.20240311)", "types-defusedxml (==0.7.0.20240218)", "types-docutils (==0.21.0.20240724)", "types-requests (>=2.30.0)"]
+test = ["cython (>=3.0)", "defusedxml (>=0.7.1)", "pytest (>=8.0)", "setuptools (>=70.0)", "typing_extensions (>=4.9)"]
 
 [[package]]
 name = "sphinxcontrib-applehelp"
@@ -3341,4 +3341,4 @@ tests-strict = ["pytest (==4.6.0)", "pytest (==4.6.0)", "pytest (==6.2.5)", "pyt
 [metadata]
 lock-version = "2.0"
 python-versions = "<3.13,>=3.10"
-content-hash = "37f49634c9f3462d2a250d6e182ae22e367bb80b51112cf8de51b230ed3f7250"
+content-hash = "c4cb324a4a42951b424024e1ac232d8dfb9dbb7dc203329eb44877e51443a929"
diff --git a/pyproject.toml b/pyproject.toml
index c3f4096..6a0ec43 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,7 +55,7 @@ safety = "^3.0.1"
 mypy = "^1.11.1"
 
 [tool.poetry.group.docs.dependencies]
-sphinx = "^7.2.6"
+sphinx = "^8.0.2"
 recommonmark = "^0.7.1"
 
 [tool.coverage.paths]