diff --git src/wp-cron.php src/wp-cron.php
index da526d2fea..0b1a989682 100644
--- src/wp-cron.php
+++ src/wp-cron.php
@@ -135,4 +135,13 @@ foreach ( $crons as $timestamp => $cronhooks ) {
 if ( _get_cron_lock() == $doing_wp_cron )
 	delete_transient( 'doing_cron' );
 
+// Remove expired transient from the website in use
+$time = time();
+$sql = "DELETE a, b FROM $wpdb->options a, $wpdb->options b
+	WHERE a.option_name LIKE %s
+	AND a.option_name NOT LIKE %s
+	AND b.option_name = CONCAT( '_transient_timeout_', SUBSTRING( a.option_name, 17 ) )
+	AND b.option_value < %d";
+	$wpdb->query( $wpdb->prepare( $sql, $wpdb->esc_like( '_transient_' ) . '%', $wpdb->esc_like ( '_transient_timeout_' ) . '%', $time ) );
+
 die();