diff --git a/src/services/tree.js b/src/services/tree.js
index 41f494927..c35c9fe6f 100644
--- a/src/services/tree.js
+++ b/src/services/tree.js
@@ -2,6 +2,7 @@
 
 const sql = require('./sql');
 const sync_table = require('./sync_table');
+const protected_session = require('./protected_session');
 
 async function validateParentChild(res, parentNoteId, childNoteId, noteTreeId = null) {
     const existing = await getExistingNoteTree(parentNoteId, childNoteId);