diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index e68e9b95..88aae693 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -3106,7 +3106,7 @@ class calendar extends rcube_plugin
 
     // establish imap connection
     $imap = $this->rc->get_storage();
-    $imap->set_mailbox($mbox);
+    $imap->set_folder($mbox);
 
     if ($uid && $mime_id) {
       $part = $imap->get_message_part($uid, $mime_id);
@@ -3166,7 +3166,7 @@ class calendar extends rcube_plugin
 
     // establish imap connection
     $imap = $this->rc->get_storage();
-    $imap->set_mailbox($mbox);
+    $imap->set_folder($mbox);
     $message = new rcube_message($uid);
 
     if ($message->headers) {
diff --git a/plugins/libcalendaring/libcalendaring.php b/plugins/libcalendaring/libcalendaring.php
index 9c9405ce..a3fc7679 100644
--- a/plugins/libcalendaring/libcalendaring.php
+++ b/plugins/libcalendaring/libcalendaring.php
@@ -1388,7 +1388,7 @@ class libcalendaring extends rcube_plugin
 
         // establish imap connection
         $imap = $this->rc->get_storage();
-        $imap->set_mailbox($mbox);
+        $imap->set_folder($mbox);
 
         if ($uid && $mime_id) {
             list($mime_id, $index) = explode(':', $mime_id);
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
index 2fb81c71..e0c167f7 100644
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -1563,7 +1563,7 @@ class tasklist extends rcube_plugin
 
         // establish imap connection
         $imap = $this->rc->get_storage();
-        $imap->set_mailbox($mbox);
+        $imap->set_folder($mbox);
         $message = new rcube_message($uid);
 
         if ($message->headers) {
@@ -1789,7 +1789,7 @@ class tasklist extends rcube_plugin
 
         // establish imap connection
         $imap = $this->rc->get_storage();
-        $imap->set_mailbox($mbox);
+        $imap->set_folder($mbox);
 
         if ($uid && $mime_id) {
             $part    = $imap->get_message_part($uid, $mime_id);