diff --git a/source/branches/CLASSV3/Model/XS/XSM_MLP.cxx b/source/branches/CLASSV3/Model/XS/XSM_MLP.cxx
index 99ce5afe8ca37cbaae3c8b9e614d2dac46166d29..e8a6a1f363b209120304317ac99164175f5249e5 100644
--- a/source/branches/CLASSV3/Model/XS/XSM_MLP.cxx
+++ b/source/branches/CLASSV3/Model/XS/XSM_MLP.cxx
@@ -259,7 +259,7 @@ TTree* XSM_MLP::CreateTMVAInputTree(IsotopicVector isotopicvector,int TimeStep)
 
 	IsotopicVector IVAccordingToUserInfoFile = isotopicvector.GetThisComposition(IVInputTMVA);
 
-	double Ntot = IVAccordingToUserInfoFile.GetTotalMass()*1e6/IVAccordingToUserInfoFile.MeanMolar()*6.02214129e23;
+	double Ntot = IVAccordingToUserInfoFile.GetSumOfAll();
 
 	IVAccordingToUserInfoFile = IVAccordingToUserInfoFile/Ntot;