diff --git a/.readthedocs.yml b/.readthedocs.yml
index b5dc5eba..0ee32009 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -9,7 +9,7 @@ build:
   tools:
     python: "3.11"
   apt_packages:
-    - graphviz
+  - graphviz
 
 python:
   install: