diff --git a/src/xchembku_api/datafaces/aiohttp.py b/src/xchembku_api/datafaces/aiohttp.py
index 23059d7..17b0eaa 100644
--- a/src/xchembku_api/datafaces/aiohttp.py
+++ b/src/xchembku_api/datafaces/aiohttp.py
@@ -1,7 +1,6 @@
 import logging
 from typing import Dict, List, Optional
 
-from dls_utilpack.callsign import callsign
 from soakdb3_api.models.crystal_well_model import (
     CrystalWellModel as Soakdb3CrystalWellModel,
 )