diff --git a/wp-includes/ms-functions.php b/wp-includes/ms-functions.php
index dfb25daa0c..9d30a7c7a2 100644
--- a/wp-includes/ms-functions.php
+++ b/wp-includes/ms-functions.php
@@ -666,7 +666,7 @@ function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 function wpmu_signup_blog( $domain, $path, $title, $user, $user_email, $meta = array() )  {
 	global $wpdb;
 
-	$key = substr( md5( time() . rand() . $domain ), 0, 16 );
+	$key = substr( md5( time() . wp_rand() . $domain ), 0, 16 );
 	$meta = serialize($meta);
 
 	$wpdb->insert( $wpdb->signups, array(
@@ -716,7 +716,7 @@ function wpmu_signup_user( $user, $user_email, $meta = array() ) {
 	// Format data
 	$user = preg_replace( '/\s+/', '', sanitize_user( $user, true ) );
 	$user_email = sanitize_email( $user_email );
-	$key = substr( md5( time() . rand() . $user_email ), 0, 16 );
+	$key = substr( md5( time() . wp_rand() . $user_email ), 0, 16 );
 	$meta = serialize($meta);
 
 	$wpdb->insert( $wpdb->signups, array(