diff --git a/.readthedocs.yml b/.readthedocs.yml
index 81128eb..ba2f9a0 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -2,8 +2,8 @@ version: 2
 
 build:
   os: ubuntu-20.04
-    tools:
-      python: "3.9"
+  tools:
+    python: "3.9"
 
 python:
   install: