diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index d0014f904..a28678b8f 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -4,3 +4,9 @@
 
 # Required
 version: 2
+
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-20.04
+  tools
+    python: "3.9"