diff --git a/app/model/ReimburseModel.py b/app/model/ReimburseModel.py
index 7795928..7ecd2db 100644
--- a/app/model/ReimburseModel.py
+++ b/app/model/ReimburseModel.py
@@ -100,9 +100,9 @@ class ReimburseModel(BasicModel, table=True):
   def amount(self) -> Decimal:
     ret = Decimal(0)
     for other_item in (self.other_list or []):
-      ret = ret + Decimal(other_item.amount)
+      ret = ret + (Decimal(other_item.amount) if other_item.amount is not None else 0)
     for travel_item in (self.travel_list or []):
-      ret = ret + Decimal(travel_item.amount)
+      ret = ret + (Decimal(travel_item.amount) if travel_item.amount is not None else 0)
     return ret
 
   @amount.setter