diff --git a/pyproject.toml b/pyproject.toml
index 8d30970..49d16a5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ dependencies = [
   "myst-parser>=5.1.0",
   "nbsphinx>=0.9.8",
   "shibuya>=2026.7.12",
-  "sphinx>=9.1.0",
+  "sphinx>=9.1.1",
   "sphinx-collections",
   "sphinx-copybutton>=0.5.2",
   "sphinx-design>=0.7.0",
diff --git a/uv.lock b/uv.lock
index fe23ba7..d9f75bb 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1,5 +1,5 @@
 version = 1
-revision = 3
+revision = 5
 requires-python = ">=3.14"
 
 [manifest]
@@ -329,7 +329,7 @@ requires-dist = [
     { name = "myst-parser", specifier = ">=5.1.0" },
     { name = "nbsphinx", specifier = ">=0.9.8" },
     { name = "shibuya", specifier = ">=2026.7.12" },
-    { name = "sphinx", specifier = ">=9.1.0" },
+    { name = "sphinx", specifier = ">=9.1.1" },
     { name = "sphinx-collections" },
     { name = "sphinx-copybutton", specifier = ">=0.5.2" },
     { name = "sphinx-design", specifier = ">=0.7.0" },
@@ -1206,7 +1206,7 @@ wheels = [
 
 [[package]]
 name = "sphinx"
-version = "9.1.0"
+version = "9.1.1"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "alabaster" },
@@ -1227,9 +1227,9 @@ dependencies = [
     { name = "sphinxcontrib-qthelp" },
     { name = "sphinxcontrib-serializinghtml" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/cd/bd/f08eb0f4eed5c83f1ba2a3bd18f7745a2b1525fad70660a1c00224ec468a/sphinx-9.1.0.tar.gz", hash = "sha256:7741722357dd75f8190766926071fed3bdc211c74dd2d7d4df5404da95930ddb", size = 8718324, upload-time = "2025-12-31T15:09:27.646Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/fc/73/567727fc8c8d85bc3adc88a246e12937cfda8d565cf1d80e85bceaa61fe5/sphinx-9.1.1.tar.gz", hash = "sha256:48b627f02908f22c601b3ba9c7b17265b4f315dd05c8bc64cd4da41183f44fbc", size = 8725638, upload-time = "2026-10-20T00:41:13.96Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/73/f7/b1884cb3188ab181fc81fa00c266699dab600f927a964df02ec3d5d1916a/sphinx-9.1.0-py3-none-any.whl", hash = "sha256:c84fdd4e782504495fe4f2c0b3413d6c2bf388589bb352d439b2a3bb99991978", size = 3921742, upload-time = "2025-12-31T15:09:25.561Z" },
+    { url = "https://files.pythonhosted.org/packages/47/18/3c66ea76da7de47e716b181c35bdbfafbd5e9af0bb247b14578e9de348e9/sphinx-9.1.1-py3-none-any.whl", hash = "sha256:f8b60013ce25017be41a509e5c2d265bc1918410061315c36b809c7f335646c0", size = 3923559, upload-time = "2026-10-20T00:41:11.288Z" },
 ]
 
 [[package]]