diff --git a/doc/_static/css/custom.css b/doc/_static/css/custom.css
index b7e4e54e881..1bc107e11c2 100644
--- a/doc/_static/css/custom.css
+++ b/doc/_static/css/custom.css
@@ -1171,3 +1171,7 @@ li>a.code-sample-link.reference.internal.current {
     text-overflow: ellipsis;
     overflow: hidden;
 }
+
+.sidebar.board-overview dl.field-list>dd code {
+    font-size: 0.9em;
+}