diff --git a/.readthedocs.yml b/.readthedocs.yml
index bf4d577..31d0d1f 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -6,9 +6,9 @@
 version: 2
 
 build:
-  os: "ubuntu-22.04"
+  os: "ubuntu-20.04"
   tools:
-    python: "3.11"
+    python: "mambaforge-4.10"
   jobs:
     pre_install:
       - git update-index --assume-unchanged docs/conf.py docs/rtd_environment.yaml