diff --git a/wp-admin/upgrade-schema.php b/wp-admin/upgrade-schema.php
index 777dd9d6a3..dbd685a25b 100644
--- a/wp-admin/upgrade-schema.php
+++ b/wp-admin/upgrade-schema.php
@@ -206,7 +206,7 @@ function populate_options() {
 	add_option('page_uris');
 	add_option('blacklist_keys');
 	add_option('comment_registration', 0);
-	add_option('open_proxy_check', 1);
+	add_option('open_proxy_check', 0);
 	add_option('rss_language', 'en');
 	add_option('html_type', 'text/html');
 	// 1.5.1
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 9fc0648844..d96c5e754c 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -1013,7 +1013,7 @@ function wp_check_filetype($filename, $mimes = null) {
 function wp_proxy_check($ipnum) {
 	if ( get_option('open_proxy_check') && isset($ipnum) ) {
 		$rev_ip = implode( '.', array_reverse( explode( '.', $ipnum ) ) );
-		$lookup = $rev_ip . '.opm.blitzed.org.';
+		$lookup = $rev_ip . '.sbl-xbl.spamhaus.org.';
 		if ( $lookup != gethostbyname( $lookup ) )
 			return true;
 	}