diff --git a/css/display-responsive-iframe-maintaining-aspect-ratio.md b/css/display-responsive-iframe-maintaining-aspect-ratio.md
index d9e80fa..3106dd9 100644
--- a/css/display-responsive-iframe-maintaining-aspect-ratio.md
+++ b/css/display-responsive-iframe-maintaining-aspect-ratio.md
@@ -21,7 +21,6 @@ while maintaining its aspect ratio using a little CSS.
 .iframe-container {
   width: 100%;
   aspect-ratio: 16 / 9;
-  border: 0; // optional
 }
 ```