diff --git a/PhysicsAnalysis/MCTruthClassifier/Root/MCTruthClassifierGen.cxx b/PhysicsAnalysis/MCTruthClassifier/Root/MCTruthClassifierGen.cxx
index 507697d3fafb5cbae3d02d1bfa305eb5637155bf..8b9ac57fae7ebb317242324432a29c0654ba8d33 100644
--- a/PhysicsAnalysis/MCTruthClassifier/Root/MCTruthClassifierGen.cxx
+++ b/PhysicsAnalysis/MCTruthClassifier/Root/MCTruthClassifierGen.cxx
@@ -754,7 +754,7 @@ ParticleOrigin MCTruthClassifier::defOrigOfMuon(const xAOD::TruthParticleContain
 
 ParticleOrigin MCTruthClassifier::defOrigOfTau(const xAOD::TruthParticleContainer& xTruthParticleContainer,
                                 const xAOD::TruthParticle* thePart,
-                                int motherPDG,
+                                int motherPDGin,
                                 MCTruthPartClassifier::Info& info) const
 {
   ATH_MSG_DEBUG("Executing DefOrigOfTau ");
@@ -780,7 +780,7 @@ ParticleOrigin MCTruthClassifier::defOrigOfTau(const xAOD::TruthParticleContaine
 
   const xAOD::TruthParticle* MotherParent(nullptr);
 
-  if (MC::isW(motherPDG) && mothOriVert != nullptr) {
+  if (MC::isW(motherPDGin) && mothOriVert != nullptr) { // FIXME motherPDGin here could in principle be inconsistent with mothOriVert
     MotherParent = MC::findMother(mother);
     int pPDG(0);
 
@@ -793,7 +793,7 @@ ParticleOrigin MCTruthClassifier::defOrigOfTau(const xAOD::TruthParticleContaine
     }
   }
 
-  motherPDG = mother->pdgId(); // FIXME assigning to non-reference function argument.
+  int motherPDG = mother->pdgId();
   info.setMotherProperties(mother);
   mothOriVert = mother->hasProdVtx() ? mother->prodVtx() : nullptr;
   partOriVert = mother->decayVtx();