diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 06269c3e453..a3f84425605 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -18,8 +18,8 @@ sphinx:
    configuration: doc/conf.py
 
 # If using Sphinx, optionally build your docs in additional formats such as PDF
-# formats:
-#    - pdf
+formats:
+   - pdf
 
 # Optionally declare the Python requirements required to build your docs
 conda: