diff --git a/app/assets/stylesheets/common/base/topic-post.scss b/app/assets/stylesheets/common/base/topic-post.scss
index 1908afc4dc6..167cbd4e455 100644
--- a/app/assets/stylesheets/common/base/topic-post.scss
+++ b/app/assets/stylesheets/common/base/topic-post.scss
@@ -31,6 +31,8 @@
   h1, h2, h3, h4, h5, h6 { margin: 30px 0 10px; }
   h1 { line-height: 1em; } /* normalize.css sets h1 font size but not line height */
   a { word-wrap: break-word; }
+  ins { background-color: dark-light-choose(scale-color($success, $lightness: 90%), scale-color($success, $lightness: -60%)); }
+  del { background-color: dark-light-choose(scale-color($danger, $lightness: 90%), scale-color($danger, $lightness: -60%)); }
 }