diff --git a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.cxx b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.cxx
index 0995303cfbb9e2c73fb97484deafeba4d1b37a56..5e8fff1d458597e4c0f229802c02acf8cb94a2bd 100644
--- a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.cxx
+++ b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.cxx
@@ -68,19 +68,6 @@ namespace IDTPM {
         track, "truthParticleLink" );
   }
 
-  /// isFake
-  bool isFakeTruth( const xAOD::TrackParticle& track,
-                    const float truthProbCut,
-                    const bool unlinkedAsFakes )
-  {
-    /// if fakes include unlinked, return true if isUnlinked is true
-    if( unlinkedAsFakes and isUnlinkedTruth( track ) ) return true;
-    float prob = getTruthMatchProb( track );
-    /// returns true if truthMatchProbability deco isn't available or
-    /// if the truth matching probability is below theshold
-    return ( prob < truthProbCut );
-  }
-
   /// isReconstructable
   bool isReconstructable( const xAOD::TruthParticle& truth,
                           const std::vector<unsigned int>& minSilHits,
diff --git a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.h b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.h
index fc5b2068586113422def791e79662606634f2c5f..98e3f311312f4789898eeb7a08862b93004ea266 100644
--- a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.h
+++ b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/OfflineObjectDecorHelper.h
@@ -82,11 +82,6 @@ namespace IDTPM {
   inline const xAOD::TruthParticle* getLinkedTruth(
       const xAOD::TruthParticle&, const float ) { return nullptr; }; // dummy - to avoid compilation errors
 
-  bool isFakeTruth( const xAOD::TrackParticle& track,
-                    const float truthProbCut=0., const bool unlinkedAsFakes=false );
-  inline bool isFakeTruth( const xAOD::TruthParticle&,
-                           const float, const bool ) { return false; }; // dummy - to avoid compilation errors
-
   bool isReconstructable( const xAOD::TruthParticle& truth,
                           const std::vector< unsigned int >& minSilHits,
                           const std::vector< float >& etaBins);
diff --git a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/TrackAnalysisPlotsMgr.cxx b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/TrackAnalysisPlotsMgr.cxx
index 402c978dd0fcb4c2af77b57fcd4fb3b658fe74cd..a9b64b23343698c6fa77eaeafb3bb918ddab61bc 100644
--- a/InnerDetector/InDetValidation/InDetTrackPerfMon/src/TrackAnalysisPlotsMgr.cxx
+++ b/InnerDetector/InDetValidation/InDetTrackPerfMon/src/TrackAnalysisPlotsMgr.cxx
@@ -366,10 +366,10 @@ StatusCode IDTPM::TrackAnalysisPlotsMgr::fillPlotsTest(
 
     /// fake rate plots (and hits on fake plots)
     bool isUnlinked = isUnlinkedTruth( *particle );
-    bool notTruthMatched = getTruthMatchProb( *particle ) < 0.5;
+    bool isFakeTruth = getTruthMatchProb( *particle ) < m_trkAnaDefSvc->truthProbCut();
     if ( isUnlinked ) {
       if( m_plots_missingTruth ) {
-        ATH_CHECK( m_plots_missingTruth->fillPlots( *particle, notTruthMatched, truthMu, actualMu, weight ) );
+        ATH_CHECK( m_plots_missingTruth->fillPlots( *particle, isFakeTruth, truthMu, actualMu, weight ) );
       }
       if( m_plots_hitsOnUnlinkedTrk ) {
         ATH_CHECK( m_plots_hitsOnUnlinkedTrk->fillPlots( *particle, truthMu, actualMu, weight ) ); 
@@ -378,10 +378,8 @@ StatusCode IDTPM::TrackAnalysisPlotsMgr::fillPlotsTest(
 
     bool doFakes = m_trkAnaDefSvc->unlinkedAsFakes() ? true : not isUnlinked;
     if( doFakes and m_plots_fakeRate ) {
-      bool isFake = isFakeTruth( *particle, m_trkAnaDefSvc->truthProbCut(),
-                                 m_trkAnaDefSvc->unlinkedAsFakes() );
-      ATH_CHECK( m_plots_fakeRate->fillPlots( *particle, isFake, truthMu, actualMu, weight ) );
-      if( m_plots_hitsOnFakeTrk and isFake ) {
+      ATH_CHECK( m_plots_fakeRate->fillPlots( *particle, isFakeTruth, truthMu, actualMu, weight ) );
+      if( m_plots_hitsOnFakeTrk and isFakeTruth ) {
         ATH_CHECK( m_plots_hitsOnFakeTrk->fillPlots( *particle, truthMu, actualMu, weight ) );
       }
     }