diff --git a/src/librustdoc/html/static/themes/ayu.css b/src/librustdoc/html/static/themes/ayu.css
index e0ab7170ea8..09ee9b4b505 100644
--- a/src/librustdoc/html/static/themes/ayu.css
+++ b/src/librustdoc/html/static/themes/ayu.css
@@ -318,6 +318,7 @@ a.test-arrow {
 	font-size: 100%;
 	color: #788797;
 	border-radius: 4px;
+	box-shadow: 0 0 0 1px #424c57,0 0 0 2px transparent;
 	background-color: rgba(255, 255, 255, 0);
 }