diff --git a/PhysicsAnalysis/JetTagging/FlavorTagDiscriminants/Root/BTagJetAugmenter.cxx b/PhysicsAnalysis/JetTagging/FlavorTagDiscriminants/Root/BTagJetAugmenter.cxx
index 2ff561bd42f1c307f26341318866cbe22dc4ce83..921d8fa3734e7a61bd68e8240e3955ce871db24f 100644
--- a/PhysicsAnalysis/JetTagging/FlavorTagDiscriminants/Root/BTagJetAugmenter.cxx
+++ b/PhysicsAnalysis/JetTagging/FlavorTagDiscriminants/Root/BTagJetAugmenter.cxx
@@ -413,7 +413,7 @@ void BTagJetAugmenter::augment(const xAOD::Jet &jet) {
       max_track_flightDirRelEta = track_flightDirRelEta;
     }
     if (secondary_jf_vtx_index >= 0) {
-      for (const ElementLink<xAOD::TrackParticleContainer> vertex_track_particle : (**m_jf_vertices(btag).at(secondary_jf_vtx_index)).track_links()) {
+      for (const ElementLink<xAOD::TrackParticleContainer>& vertex_track_particle : (**m_jf_vertices(btag).at(secondary_jf_vtx_index)).track_links()) {
         if (*vertex_track_particle == &track_particle) {
           secondaryVtx_track_number++;
           TLorentzVector track_fourVector;