diff --git a/VectoCore/VectoCore/OutputData/XML/XMLDeclarationReport.cs b/VectoCore/VectoCore/OutputData/XML/XMLDeclarationReport.cs
index 94eb0b24302e3cb824756009de2f173d96aff83d..d0fd0c53a682a9a243e005342f693c47419937b8 100644
--- a/VectoCore/VectoCore/OutputData/XML/XMLDeclarationReport.cs
+++ b/VectoCore/VectoCore/OutputData/XML/XMLDeclarationReport.cs
@@ -237,7 +237,7 @@ namespace TUGraz.VectoCore.OutputData.XML
 
 				WeightingGroup = DeclarationData.WeightingGroup.Lookup(
 						modelData.VehicleData.VehicleClass, modelData.VehicleData.SleeperCab.Value,
-						modelData.EngineData.RatedPowerDeclared);
+						modelData.EngineData?.RatedPowerDeclared ?? Watt.Create(0));
 			}
 
 			_weightingFactors = WeightingGroup == WeightingGroup.Unknown