diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 346d10afd3..82a1206dd0 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -465,6 +465,8 @@ function clean_blog_cache( $blog ) {
 	 * @param string  $domain_path_key md5 hash of domain and path.
 	 */
 	do_action( 'clean_site_cache', $blog_id, $blog, $domain_path_key );
+
+	wp_cache_set( 'last_changed', microtime(), 'sites' );
 }
 
 /**
diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
index 84a4063488..83b1791674 100644
--- a/src/wp-includes/ms-functions.php
+++ b/src/wp-includes/ms-functions.php
@@ -1147,6 +1147,8 @@ function wpmu_create_blog( $domain, $path, $title, $user_id, $meta = array(), $s
 	 */
 	do_action( 'wpmu_new_blog', $blog_id, $user_id, $domain, $path, $site_id, $meta );
 
+	wp_cache_set( 'last_changed', microtime(), 'sites' );
+
 	return $blog_id;
 }