diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index c5a8914..bf326a4 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -2,6 +2,8 @@ version: 2
 
 build:
   os: ubuntu-20.04
+  apt_packages:
+    - fonts-liberation
   tools:
     python: "3.10"