diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index e1bd371..2e5c765 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -13,6 +13,9 @@ build:
     # nodejs: "20"
     # rust: "1.70"
     # golang: "1.20"
+  apt_packages:
+    - graphviz
+    - openjdk-11-jre
 
 # Build documentation in the "docs/" directory with Sphinx
 sphinx: