diff --git a/doc/_themes/sphinx13/static/sphinx13.css b/doc/_themes/sphinx13/static/sphinx13.css
index c8fb2e5c99b..789a5d4f312 100644
--- a/doc/_themes/sphinx13/static/sphinx13.css
+++ b/doc/_themes/sphinx13/static/sphinx13.css
@@ -372,7 +372,8 @@ div.quotebar {
     margin-left: 1em;
 }
 
-div.topic {
+div.topic,
+aside.topic {
     background-color: #f8f8f8;
 }