diff --git a/cms/static/sass/elements/_xblocks.scss b/cms/static/sass/elements/_xblocks.scss
index ed77384405..fe789bfe2f 100644
--- a/cms/static/sass/elements/_xblocks.scss
+++ b/cms/static/sass/elements/_xblocks.scss
@@ -424,6 +424,7 @@
     .xblock-render {
       margin: ($baseline/2);
       padding: ($baseline/2);
+      overflow: hidden;
     }
 
     // STATE: container/component with children - abbreviated preview