diff --git a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
index c72c0720..ffce9b5e 100644
--- a/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/lib/rcube_kolab_contacts.php
@@ -337,7 +337,7 @@ class rcube_kolab_contacts extends rcube_addressbook
                 }
             }
         }
-        else {
+        else if (isset($this->dataset)) {
             $this->result->count = isset($query) ? $this->storagefolder->count($query) : 0;
             foreach ($this->dataset as $idx => $record) {
                 $this->result->add($this->_to_rcube_contact($record));