diff --git a/.readthedocs.yml b/.readthedocs.yml
index eb791066..939715a9 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -16,8 +16,9 @@ sphinx:
     configuration: doc/conf.py
     fail_on_warning: true
 
-# Optionally build your docs in additional formats such as PDF and ePub
-formats: all
+# Optionally build your docs in additional formats such as PDF and ePub.
+# Note ePub format does not like include files.
+formats: []
 
 # Optionally set the version of Python and requirements required to build your docs
 python: