diff --git a/wp-admin/user-edit.php b/wp-admin/user-edit.php
index 628aadb076..1166621f9f 100644
--- a/wp-admin/user-edit.php
+++ b/wp-admin/user-edit.php
@@ -64,7 +64,7 @@ $new_user_login  = $_POST['new_user_login'];
 $new_firstname   = $_POST['new_firstname'];
 $new_lastname    = $_POST['new_lastname'];
 $new_nickname    = $_POST['new_nickname'];
-$new_nicename    = sanitize_title($new_nickname);
+$new_nicename    = sanitize_title($new_nickname, $user_id);
 $new_icq         = $_POST['new_icq'];
 $new_aim         = $_POST['new_aim'];
 $new_msn         = $_POST['new_msn'];
diff --git a/wp-admin/users.php b/wp-admin/users.php
index 5ff743fa58..0c143eee86 100644
--- a/wp-admin/users.php
+++ b/wp-admin/users.php
@@ -70,7 +70,9 @@ case 'adduser':
 		return false;
 	}
 
-    $user_nicename = sanitize_title($user_nickname);
+	$user_ID = $wpdb->get_var("SELECT ID FROM $wpdb->users ORDER BY ID DESC LIMIT 1") + 1;
+
+	$user_nicename = sanitize_title($user_nickname, $user_ID);
 	$user_uri = preg_match('/^(https?|ftps?|mailto|news|gopher):/is', $user_uri) ? $user_uri : 'http://' . $user_uri;
 	$now = gmdate('Y-m-d H:i:s');
 	$new_users_can_blog = get_settings('new_users_can_blog');