diff --git a/product/ERP5/Document/TradeModelLine.py b/product/ERP5/Document/TradeModelLine.py
index 4a40684748744a484f9b08d12e641d4b9ad8f0f7..7e400ad6a00dc0fbf25e3fed1111f0ae8f7b2b0b 100644
--- a/product/ERP5/Document/TradeModelLine.py
+++ b/product/ERP5/Document/TradeModelLine.py
@@ -89,7 +89,7 @@ class TradeModelLine(Predicate, XMLMatrix, Amount):
     script_name = self.getCalculationScriptId()
     if script_name is None:
       # if model line script is None, get the default model script
-      model = context.getSpecialiseValue().getEffectiveModel()
+      model = self.getParentValue()
       script_name = model.getCalculationScriptId()
     if script_name is None:
       return None