diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index f83760cce..cc2b2817b 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -20,8 +20,8 @@ sphinx:
    configuration: doc/source/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
 python: