diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index ffb45361..685e47e7 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -6,6 +6,8 @@ version: 2
 
 build:
   os: "ubuntu-22.04"
+  apt_packages:
+    - locales
   tools:
     python: "3.10"
   commands: