diff --git a/.readthedocs.yml b/.readthedocs.yml
index 6cfbf5d31..9332efdac 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,6 +1,7 @@
 version: 2
 
-formats: all
+formats:
+  - epub
 
 python:
   version: 3.7