diff --git a/.readthedocs.yml b/.readthedocs.yml
index 116ccff..081e7bc 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,7 +1,9 @@
 version: 2
 
 build:
-    image: latest
+    os: "ubuntu-22.04"
+    tools:
+        python: "mambaforge-22.9"
 
 conda:
     environment: .readthedocs_conda_env.yml
@@ -11,7 +13,6 @@ sphinx:
     fail_on_warning: false
 
 python:
-    version: 3.8
     install: 
         - method: setuptools
           path: .
diff --git a/.readthedocs_conda_env.yml b/.readthedocs_conda_env.yml
index 4826491..9a60ffb 100644
--- a/.readthedocs_conda_env.yml
+++ b/.readthedocs_conda_env.yml
@@ -2,7 +2,7 @@ name: iris-dev
 
 channels:
   - conda-forge
-
+  - nodefaults
 dependencies:
   - python=3.8
-  - iris
\ No newline at end of file
+  - iris