diff --git a/docs/requirements.txt b/docs/requirements.txt
index f7fa14c9..0fa4d4f8 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
 shibuya==2025.8.16
-sphinx==7.4.7
+sphinx==9.0.0
 sphinx-click==6.0.0
 myst_parser==4.0.1
 sphinx-copybutton==0.5.2