diff --git a/doc/source/conf.py b/doc/source/conf.py
index f7403592..1c4b05fd 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -199,6 +199,7 @@ def _reset_modules_hook(gallery_conf, fname, when):
 # https://github.com/sphinx-doc/sphinx/issues/12300
 suppress_warnings = ["config.cache"]
 
+autodoc_use_legacy_class_based = True
 
 # -- Options for HTML output -------------------------------------------------
 html_short_title = html_title = "PyFluent-Visualization"
diff --git a/requirements/requirements_doc.txt b/requirements/requirements_doc.txt
index a89bcb83..6f228c0f 100644
--- a/requirements/requirements_doc.txt
+++ b/requirements/requirements_doc.txt
@@ -1,4 +1,4 @@
-Sphinx==8.2.3
+Sphinx==9.0.1
 jupyter_sphinx==0.5.3
 numpydoc==1.10.0
 ansys-sphinx-theme==1.7.2