diff --git a/program/lib/Roundcube/rcube_imap.php b/program/lib/Roundcube/rcube_imap.php
index dfcfb5122..8d451111c 100644
--- a/program/lib/Roundcube/rcube_imap.php
+++ b/program/lib/Roundcube/rcube_imap.php
@@ -62,7 +62,6 @@ class rcube_imap extends rcube_storage
     protected $sort_field = '';
     protected $sort_order = 'DESC';
     protected $struct_charset;
-    protected $msg_headers = array();
     protected $search_set;
     protected $search_string = '';
     protected $search_charset = '';