diff --git a/.readthedocs.yml b/.readthedocs.yml
index b82c9e71..52da4cd5 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -9,13 +9,13 @@ build:
   tools:
     python: "miniconda3-4.7"
 
-
 conda:
   environment: docs/source/environment.yml
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
+  builder: html
   configuration: docs/source/conf.py
-  fail_on_warning: false
+  fail_on_warning: true