diff --git a/src/wp-content/themes/twentyfifteen/css/blocks.css b/src/wp-content/themes/twentyfifteen/css/blocks.css
index e5b3af47b8..be2d8ffef6 100644
--- a/src/wp-content/themes/twentyfifteen/css/blocks.css
+++ b/src/wp-content/themes/twentyfifteen/css/blocks.css
@@ -395,6 +395,10 @@ p.has-drop-cap:not(:focus)::first-letter {
 	vertical-align: baseline;
 }
 
+.is-style-outline .wp-block-button__link {
+	border: 2px solid;
+}
+
 .entry-content .wp-block-button:not(.is-style-outline) .wp-block-button__link {
 	border: 0;
 }