diff --git a/csst_common/data_manager.py b/csst_common/data_manager.py
index 7591f0574c547bdae255b7231b393d3bf67a0be3..b1052139b5b6196bc55ae6000f1fc43d538e183f 100644
--- a/csst_common/data_manager.py
+++ b/csst_common/data_manager.py
@@ -300,7 +300,7 @@ class CsstMbiDataManager:
             print(os.path.exists(dm.l0_log(detector=detector)))
             print("----- L1 images -----")
             print(dm.l1_detector(detector, post="img.fits"))
-        return
+        return dm
 
 
 if __name__ == "__main__":