diff --git a/pyproject.toml b/pyproject.toml
index b08afbc..4c7b6ac 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -57,7 +57,7 @@ development = [
 documentation = [
   "autodocsumm==0.2.14; python_version > '3.11'",
   "myst_parser==4.0.1; python_version > '3.11'",
-  "sphinx==8.2.3; python_version > '3.11'",
+  "sphinx==9.1.0; python_version > '3.11'",
   "sphinx-autodoc-typehints==3.1.0; python_version > '3.11'",
   "sphinx-gallery==0.19.0; python_version > '3.11'",
   "sphinx-jinja2-compat==0.4.1; python_version > '3.11'",