diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index b4be0228..cc50a4d1 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -7,7 +7,7 @@ version: 2
 
 # Set the OS, Python version and other tools you might need
 build:
-  os: ubuntu-latest
+  os: ubuntu-20.04
   tools:
     python: "3.8"
     # You can also specify other tool versions: