diff --git a/transfer_service/retrieve_preprocessor.py b/transfer_service/retrieve_preprocessor.py
index 9bd368a0f233e1e7ba7c0b60c069abcf395238ee..ad5415980b30d85261e7ef4d490f3ecd74c9e461 100644
--- a/transfer_service/retrieve_preprocessor.py
+++ b/transfer_service/retrieve_preprocessor.py
@@ -1,5 +1,8 @@
 #!/usr/bin/env python
 
+import json
+import os
+
 from config import Config
 from db_connector import DbConnector
 from task_executor import TaskExecutor