diff --git a/imap.php b/imap.php
index ed55a4a..0a7e351 100644
--- a/imap.php
+++ b/imap.php
@@ -44,7 +44,7 @@ class imap
     if ($password === null)
       throw new Exception ("No password provided for IMAP server", 500);
     $imapssl = ($imapssl !== false) ? "/ssl" : "";
-    $imapcertvalidate = ($imapcertvalidate !== false) ? "/novalidate-cert" : "";
+    $imapcertvalidate = ($imapcertvalidate === false) ? "/novalidate-cert" : "";
     $this->mailbox = "{"."$imapserver:$imapport/imap$imapssl$imapcertvalidate".
                      "/user=$username}";
     if (! array_key_exists ($this->mailbox, self::$instance))
@@ -174,6 +174,7 @@ class imap
     $res = array_map (function ($folder) {
                      return mb_convert_encoding ($folder, "UTF-8", "UTF7-IMAP");
                      }, $res);
+    natsort ($res);
     return $res;
   }