diff --git a/plugin/notes/speaker-view.html b/plugin/notes/speaker-view.html
index 3cf492d..0c77390 100644
--- a/plugin/notes/speaker-view.html
+++ b/plugin/notes/speaker-view.html
@@ -368,6 +368,10 @@
window.addEventListener( 'message', function( event ) {
+ if (window.location.origin !== event.origin){
+ return;
+ }
+
clearTimeout( connectionTimeout );
connectionStatus.style.display = 'none';