diff --git a/docs/pyproject.toml b/docs/pyproject.toml
index c1bfa553..de512193 100644
--- a/docs/pyproject.toml
+++ b/docs/pyproject.toml
@@ -18,7 +18,7 @@ dependencies = [
     "myst-parser==5.0.0",
     "rstcheck[sphinx]==6.2.5",
     "rstfmt==0.0.14",
-    "Sphinx==8.2.3",
+    "Sphinx==9.1.0",
     "sphinx-copybutton==0.5.2",
 ]