diff --git a/.readthedocs.yml b/.readthedocs.yml
index cc69854..9f3801b 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -4,3 +4,8 @@ python:
   - path: .
     extra_requirements:
       - docs
+
+# workaround for stale Python version (readthedocs/readthedocs.org#9623)
+build:
+  tools:
+    python: 3