diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index c8e9ec46..b81e998d 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -4,7 +4,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.10"
+    python: 3.9
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx: