diff --git a/.readthedocs.yml b/.readthedocs.yml
index 515a3c9bf..668ca192f 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -3,6 +3,8 @@ build:
   os: ubuntu-22.04
   tools:
     python: "3.12"
+  apt_packages:
+    - graphviz
 
 python:
   install: