diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index d9e1988..eda429c 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -8,7 +8,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.12"
+    python: "3.9"
     # You can also specify other tool versions:
     # nodejs: "20"
     # rust: "1.70"
diff --git a/docs/requirements.pip b/docs/requirements.pip
index e733f73..446f576 100644
--- a/docs/requirements.pip
+++ b/docs/requirements.pip
@@ -1,3 +1,3 @@
-sphinx
+sphinx==3.5.2
 django
 sphinx_issues