diff --git a/framework/core/less/forum/Post.less b/framework/core/less/forum/Post.less
index 31201f8bd..2a1d6d2fa 100644
--- a/framework/core/less/forum/Post.less
+++ b/framework/core/less/forum/Post.less
@@ -138,7 +138,7 @@
     font-size: 100%;
     font-weight: bold;
   }
-  img {
+  img, iframe {
     max-width: 100%;
   }
 }