diff --git a/src/wp-includes/sitemaps/class-wp-sitemaps-stylesheet.php b/src/wp-includes/sitemaps/class-wp-sitemaps-stylesheet.php
index 28c7936a36..e81529af07 100644
--- a/src/wp-includes/sitemaps/class-wp-sitemaps-stylesheet.php
+++ b/src/wp-includes/sitemaps/class-wp-sitemaps-stylesheet.php
@@ -265,7 +265,13 @@ XSL;
 						color: #444;
 					}
 
+					#sitemap {
+						max-width: 980px;
+						margin: 0 auto;
+					}
+
 					#sitemap__table {
+						width: 100%;
 						border: solid 1px #ccc;
 						border-collapse: collapse;
 					}