diff --git a/program/include/rcube_imap.php b/program/include/rcube_imap.php
index 3e2abe71e..234e8d884 100644
--- a/program/include/rcube_imap.php
+++ b/program/include/rcube_imap.php
@@ -3553,7 +3553,7 @@ class rcube_imap extends rcube_storage
      * @param string $key  Cache key
      * @param mixed  $data Data
      */
-    protected function update_cache($key, $data)
+    public function update_cache($key, $data)
     {
         if ($cache = $this->get_cache_engine()) {
             $cache->set($key, $data);