diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index e093fa93d3..8540be6baf 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -5,6 +5,11 @@
 # Required: the version of this file's schema.
 version: 2
 
+build:
+   os: "ubuntu-20.04"
+   tools:
+      python: "3.8"
+
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
   configuration: docs/conf.py
@@ -17,6 +22,5 @@ formats:
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: "3.8"
   install:
   - requirements: requirements/doc.txt