diff --git a/.readthedocs.yml b/.readthedocs.yml
index 04d5d1a44..4fb69f672 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -6,6 +6,8 @@ sphinx:
   builder: dirhtml
 
 build:
-  # First RTD build env which includes a rust toolchain
-  image: "7.0"
+  # readdocs master now includes a rust toolchain
+  os: "ubuntu-20.04"
+  tools:
+    python: "3.9"