diff --git a/.readthedocs.yml b/.readthedocs.yml
index b2b51e50..0e04f409 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,7 +1,11 @@
 version: 2
 
+build:
+   os: ubuntu-20.04
+   tools:
+     python: "3.8"
+
 python:
-    version: "3.8"
     install:
         - method: pip
           path: .