diff --git a/.readthedocs.yml b/.readthedocs.yml
index 672bc2063..c123a1939 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,6 +1,7 @@
 version: 2
 
 sphinx:
+  builder: htmldir
   configuration: docs/html/conf.py
 
 python: