diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index e69aef46a3771b497d4e8ce327b5452757e8ae34..c4a2ad06cb63d793a1783fb9df5ce8642acd2aec 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -440,7 +440,7 @@ class CsstMsDataManager:
             else:
                 return self.path_aux.format(detector, "bias")
         else:
-            return self.custom_bias(detector)
+            return self.custom_bias.format(detector)
 
     def get_dark(self, detector=6):
         """ get dark data """
@@ -450,7 +450,7 @@ class CsstMsDataManager:
             else:
                 return self.path_aux.format(detector, "dark")
         else:
-            return self.custom_dark(detector)
+            return self.custom_dark.format(detector)
 
     def get_flat(self, detector=6):
         """ get flat data """
@@ -460,7 +460,7 @@ class CsstMsDataManager:
             else:
                 return self.path_aux.format(detector, "flat")
         else:
-            return self.custom_flat(detector)
+            return self.custom_flat.format(detector)
 
     def get_axeconf(self):
         if os.uname()[1] == "dandelion":