diff --git a/app/assets/stylesheets/application/onebox.scss b/app/assets/stylesheets/application/onebox.scss
index 0ea9f94cc60..6984d4c6a2f 100644
--- a/app/assets/stylesheets/application/onebox.scss
+++ b/app/assets/stylesheets/application/onebox.scss
@@ -46,7 +46,7 @@ a.loading-onebox {
       margin: 0px !important;
     }
     img.thumbnail {
-      width: 25%;
+      max-width: 25%;
       height: auto;
     }
     code {