diff --git a/admin/inc/class.admin_account.inc.php b/admin/inc/class.admin_account.inc.php
index 8f7ef7ceb6..464095a2f8 100644
--- a/admin/inc/class.admin_account.inc.php
+++ b/admin/inc/class.admin_account.inc.php
@@ -115,7 +115,7 @@ class admin_account
 	 */
 	public static function addressbook_pre_save(&$content)
 	{
-		if ($content['old_account'] && !array_diff_assoc($content['old_account'], $content))
+		if ($content['old_account'] && $content['old_account'] == array_diff_key($content, $content['old_account']))
 		{
 			return '';	// no need to save account data, if nothing changed
 		}