diff --git a/imap.php b/imap.php
index 0a7e351..ddf5f7d 100644
--- a/imap.php
+++ b/imap.php
@@ -82,7 +82,7 @@ class imap
     if ($this->mailbox === null)
       throw new Exception ("IMAP server not connected", 500);
     $list = array_keys ($this->foldersListWithAttr ());
-    natsort ($list);
+    sort ($list);
     return $list;
   }
 
@@ -174,7 +174,7 @@ class imap
     $res = array_map (function ($folder) {
                      return mb_convert_encoding ($folder, "UTF-8", "UTF7-IMAP");
                      }, $res);
-    natsort ($res);
+    sort ($res);
     return $res;
   }