diff --git a/plugins/kolab_addressbook/drivers/kolab/kolab_contacts.php b/plugins/kolab_addressbook/drivers/kolab/kolab_contacts.php
index 369309ef..c125e334 100644
--- a/plugins/kolab_addressbook/drivers/kolab/kolab_contacts.php
+++ b/plugins/kolab_addressbook/drivers/kolab/kolab_contacts.php
@@ -476,6 +476,7 @@ class kolab_contacts extends rcube_addressbook
         }
 
         // advanced search
+        $advanced = false;
         if (is_array($value)) {
             $advanced = true;
             $value = array_map('mb_strtolower', $value);
diff --git a/plugins/libkolab/lib/kolab_format_contact.php b/plugins/libkolab/lib/kolab_format_contact.php
index bf82aa03..82e5bee3 100644
--- a/plugins/libkolab/lib/kolab_format_contact.php
+++ b/plugins/libkolab/lib/kolab_format_contact.php
@@ -310,6 +310,7 @@ class kolab_format_contact extends kolab_format
 
         // organisation related properties (affiliation)
         $orgs = $this->obj->affiliations();
+        $org = null;
         if ($orgs->size()) {
             $org = $orgs->get(0);
             $object['organization']   = $org->organisation();
diff --git a/plugins/libkolab/lib/kolab_storage_folder.php b/plugins/libkolab/lib/kolab_storage_folder.php
index 4a30b8ba..55457621 100644
--- a/plugins/libkolab/lib/kolab_storage_folder.php
+++ b/plugins/libkolab/lib/kolab_storage_folder.php
@@ -69,7 +69,7 @@ class kolab_storage_folder extends kolab_storage_folder_api
         }
 
         $oldtype = $this->type;
-        list($this->type, $suffix) = explode('.', $type_annotation);
+        list($this->type, $suffix) = array_pad(explode('.', $type_annotation), 2, null);
         $this->default      = $suffix == 'default';
         $this->subtype      = $this->default ? '' : $suffix;
         $this->id           = kolab_storage::folder_id($name);