diff --git a/js/reveal.js b/js/reveal.js
index 57fe29d9..fce3dbc3 100644
--- a/js/reveal.js
+++ b/js/reveal.js
@@ -3862,6 +3862,7 @@
 					iframe.setAttribute( 'allowfullscreen', '' );
 					iframe.setAttribute( 'mozallowfullscreen', '' );
 					iframe.setAttribute( 'webkitallowfullscreen', '' );
+					iframe.setAttribute( 'allow', 'autoplay' );
 
 					iframe.setAttribute( 'data-src', backgroundIframe );