diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index c38e56adb7..b048db3836 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4128,6 +4128,7 @@ function _search_terms_tidy($t) {
  *
  * Useful for returning true to filters easily
  *
+ * @since 3.0.0
  * @see __return_false()
  * @return bool true
  */
@@ -4140,6 +4141,7 @@ function __return_true() {
  *
  * Useful for returning false to filters easily
  *
+ * @since 3.0.0
  * @see __return_true()
  * @return bool false
  */
@@ -4147,6 +4149,19 @@ function __return_false() {
 	return false;
 }
 
+/**
+ * Returns 0
+ *
+ * Useful for returning 0 to filters easily
+ *
+ * @since 3.0.0
+ * @see __return_zero()
+ * @return int 0
+ */
+function __return_zero() {
+	return 0;
+}
+
 /**
  * Send a HTTP header to disable content type sniffing in browsers which support it.
  *
diff --git a/wp-login.php b/wp-login.php
index b6b11a429a..c9756a3aef 100644
--- a/wp-login.php
+++ b/wp-login.php
@@ -42,7 +42,7 @@ function login_header($title = 'Log In', $message = '', $wp_error = '') {
 	global $error, $is_iphone, $interim_login, $current_site;
 
 	// Don't index any of these forms
-	add_filter( 'pre_option_blog_public', create_function( '$a', 'return 0;' ) );
+	add_filter( 'pre_option_blog_public', '__return_zero' );
 	add_action( 'login_head', 'noindex' );
 
 	if ( empty($wp_error) )