diff --git a/source b/source
index 5344927e2db..7dce955edd4 100644
--- a/source
+++ b/source
@@ -11516,7 +11516,7 @@ console.assert(image.height === 200);</code></pre>
 
   <p>These categories are related as follows:</p>
 
-  <p><object width="1000" height="288" data="/images/content-venn.svg"></object></p>
+  <p><iframe width="1000" height="288" src="/images/content-venn.svg"></iframe></p>
 
   <p>Sectioning content, heading content, phrasing content, embedded content, and interactive
   content are all types of flow content. Metadata is sometimes flow content. Metadata and
diff --git a/styles.css b/styles.css
index a152c0fcbde..0aa363781e8 100644
--- a/styles.css
+++ b/styles.css
@@ -1,3 +1,5 @@
+iframe { border: 0; }
+
 .bad, .bad *:not(.X\58X) { color: gray; }
 
 .applies .yes, .yesno .yes { background: yellow; }