diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index 51847914479cfe52c0e4b83e0a5a55e4c8d4a57b..d0dabcf15dd75b780c566ef85bd3a481c6cee9c4 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -574,7 +574,7 @@ class CsstMsDataManager:
                 fp = os.path.join(
                     self.path_aux,
                     "C6.2_ref_crds",
-                    "csst_msc_ms_{}_{:02d}_{:06d}.fits".format(detector, detector, 1)
+                    "csst_msc_ms_{}_{:02d}_{:06d}.fits".format(ref_type, detector, 1)
                 )
                 assert os.path.exists(fp), f"File not found: [{fp}]"
                 refs[ref_type] = fp