diff --git a/pyproject.toml b/pyproject.toml
index d724b7f..a79022b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,7 +13,7 @@ dependencies = [
     "matplotlib>=3.10.1",
     "myst-parser[linkify]==2.0.0",
     "shibuya==2025.2.28",
-    "sphinx==7.2.6",
+    "sphinx==8.2.3",
     "sphinx-copybutton==0.5.2",
     "sphinx-design==0.5.0",
     "sphinx-sitemap==2.5.1",