diff --git a/lib/kolab_sync_storage_kolab4.php b/lib/kolab_sync_storage_kolab4.php
--- a/lib/kolab_sync_storage_kolab4.php
+++ b/lib/kolab_sync_storage_kolab4.php
@@ -66,6 +66,9 @@
         // Inject user+password to the URL, there's no other way to pass it to the DAV client
         $url = str_replace('://', '://' . rawurlencode($sync->username) . ':' . rawurlencode($sync->password) . '@', $url);
 
+        // The default matches e.g. /dav/calendars/user/john@kolab.org/Default/
+        $this->defaultFolderRegex = $sync->config->get('activesync_dav_default_folder_regex', "/\/.*\/user\/.*\/Default\/$/");
+
         $this->davStorage = new kolab_storage_dav($url); // DAV
         $this->storage = $sync->get_storage(); // IMAP
 
@@ -350,6 +353,11 @@
             return parent::folder_data($folder, $type);
         }
 
+        // Dav doesn't have folder type annotations, so we find default folders by regex
+        if (preg_match($this->defaultFolderRegex, $folder->href)) {
+            $type = "$type.default";
+        }
+
         // DAV folders
         return [
             'serverId'    => "DAV:{$type}:{$folder->id}",
diff --git a/tests/Sync/FoldersTest.php b/tests/Sync/FoldersTest.php
--- a/tests/Sync/FoldersTest.php
+++ b/tests/Sync/FoldersTest.php
@@ -76,15 +76,15 @@
 
         if ($this->isStorageDriver('kolab4')) {
             $folders = [
-                ['Calendar', Syncroton_Command_FolderSync::FOLDERTYPE_CALENDAR_USER_CREATED],
+                ['Calendar', Syncroton_Command_FolderSync::FOLDERTYPE_CALENDAR],
                 // Note: Kolab 4 with Cyrus DAV uses Addressbook, but Kolab 3 with iRony would use 'Contacts'
-                ['/^(Contacts|Addressbook)$/', Syncroton_Command_FolderSync::FOLDERTYPE_CONTACT_USER_CREATED],
+                ['/^(Contacts|Addressbook)$/', Syncroton_Command_FolderSync::FOLDERTYPE_CONTACT],
                 ['INBOX', Syncroton_Command_FolderSync::FOLDERTYPE_INBOX],
                 ['Drafts', Syncroton_Command_FolderSync::FOLDERTYPE_DRAFTS],
                 ['Sent', Syncroton_Command_FolderSync::FOLDERTYPE_SENTMAIL],
                 ['Trash', Syncroton_Command_FolderSync::FOLDERTYPE_DELETEDITEMS],
                 // Note: For now Kolab 4 uses the same Calendar folder for calendar and tasks
-                ['/^(Tasks|Calendar)$/', Syncroton_Command_FolderSync::FOLDERTYPE_TASK_USER_CREATED],
+                ['/^(Tasks|Calendar)$/', Syncroton_Command_FolderSync::FOLDERTYPE_TASK],
             ];
         }