diff --git a/.readthedocs.yml b/.readthedocs.yml
index eda0c9a0..36eef22f 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -15,7 +15,7 @@ sphinx:
 
 # Optionally build your docs in additional formats such as PDF and ePub
 formats: 
-  -htmlzip
+  - htmlzip
 
 # Optionally set the version of Python and requirements required to build your docs
 python: