diff --git a/jupyter_book/book_template/_includes/js/thebelab.html b/jupyter_book/book_template/_includes/js/thebelab.html
index 4966dc5cb8f74a96db1b142041d96ece2663ac63..65ef2be9e3df2539a1837c0125c52e0b10c9f56d 100644
--- a/jupyter_book/book_template/_includes/js/thebelab.html
+++ b/jupyter_book/book_template/_includes/js/thebelab.html
@@ -19,7 +19,7 @@
       }
     }
 </script>
-<script src="https://unpkg.com/thebelab@0.4.0/lib/index.js"></script>
+<script src="https://unpkg.com/thebelab@0.4.0/lib/index.js" async></script>
 <script>
     /**
      * Add attributes to Thebelab blocks