diff --git a/deepmd/dpmodel/model/make_model.py b/deepmd/dpmodel/model/make_model.py
index 36790bd36f..e0f7201886 100644
--- a/deepmd/dpmodel/model/make_model.py
+++ b/deepmd/dpmodel/model/make_model.py
@@ -30,6 +30,7 @@
     OutputVariableCategory,
     OutputVariableOperation,
     check_operation_applied,
+    FittingOutputDef,
 )
 from deepmd.dpmodel.utils import (
     build_neighbor_list,