diff --git a/wp-includes/comment.php b/wp-includes/comment.php
index 49406f61c7d0..3fa944397ced 100644
--- a/wp-includes/comment.php
+++ b/wp-includes/comment.php
@@ -399,14 +399,14 @@ function get_comment_statuses( ) {
  *
  * @since 1.5.0
  * @uses $wpdb
- * @global array $cache_lastcommentmodified
  *
  * @param string $timezone Which timezone to use in reference to 'gmt', 'blog',
  *		or 'server' locations.
  * @return string Last comment modified date.
  */
 function get_lastcommentmodified($timezone = 'server') {
-	global $cache_lastcommentmodified, $wpdb;
+	global $wpdb;
+	static $cache_lastcommentmodified = array();
 
 	if ( isset($cache_lastcommentmodified[$timezone]) )
 		return $cache_lastcommentmodified[$timezone];
diff --git a/wp-settings.php b/wp-settings.php
index cb950184f842..1e5751fa5b58 100644
--- a/wp-settings.php
+++ b/wp-settings.php
@@ -39,9 +39,6 @@
 // Turn register_globals off.
 wp_unregister_GLOBALS();
 
-// Ensure these global variables do not exist so they do not interfere with WordPress.
-unset( $wp_filter, $cache_lastcommentmodified );
-
 // Standardize $_SERVER variables across setups.
 wp_fix_server_vars();