diff --git a/pyproject.toml b/pyproject.toml
index 6c15c53fc..fe181552b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,7 @@ classifiers = [
 ]
 dependencies = [
     "Sphinx>=4.0.0",
-    "pydata-sphinx-theme==0.11.0",
+    "pydata-sphinx-theme==0.9.0",
     "Jinja2>=3.1.2",
 ]