diff --git a/program/lib/Roundcube/rcube_imap_generic.php b/program/lib/Roundcube/rcube_imap_generic.php
index bce4cd4e2..f9a62f010 100644
--- a/program/lib/Roundcube/rcube_imap_generic.php
+++ b/program/lib/Roundcube/rcube_imap_generic.php
@@ -48,6 +48,8 @@ class rcube_imap_generic
         '*'        => '\\*',
     );
 
+    public static $mupdate;
+
     private $fp;
     private $host;
     private $logged = false;
@@ -3156,6 +3158,11 @@ class rcube_imap_generic
         }
 
         foreach ($data as $entry) {
+            // Workaround cyrus-murder bug, the entry[2] string needs to be escaped
+            if (self::$mupdate) {
+                $entry[2] = addcslashes($entry[2], '\\"');
+            }
+
             // ANNOTATEMORE drafts before version 08 require quoted parameters
             $entries[] = sprintf('%s (%s %s)', $this->escape($entry[0], true),
                 $this->escape($entry[1], true), $this->escape($entry[2], true));
@@ -3720,6 +3727,10 @@ class rcube_imap_generic
             $this->prefs['literal+'] = true;
         }
 
+        if (preg_match('/(\[| )MUPDATE=.*/', $str)) {
+            self::$mupdate = true;
+        }
+
         if ($trusted) {
             $this->capability_readed = true;
         }