diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 620706682..e3a7ebf71 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -24,3 +24,8 @@ build:
 
 sphinx:
   configuration: docs/conf.py
+
+# Auxiliary formats to export to (in addition to the default HTML output).
+formats:
+  - pdf
+