diff --git a/.readthedocs.yml b/.readthedocs.yml
index bcbf579..009f8bf 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -12,7 +12,7 @@ sphinx:
 build:
   os: "ubuntu-20.04"
   tools:
-    python: "3.8"
+    python: "3.9"
   jobs:
     post_install:
       - pip install poetry