diff --git a/Event/xAOD/xAODTracking/Root/TrackParticleAuxContainer_v2.cxx b/Event/xAOD/xAODTracking/Root/TrackParticleAuxContainer_v2.cxx
index f7ffc6f9db15507c827e20fea554d7e185028188..e8600e48fc671c58b2568184a0ab9fcbf27e24dc 100644
--- a/Event/xAOD/xAODTracking/Root/TrackParticleAuxContainer_v2.cxx
+++ b/Event/xAOD/xAODTracking/Root/TrackParticleAuxContainer_v2.cxx
@@ -82,7 +82,7 @@ namespace xAOD {
       AUX_VARIABLE( numberOfTRTDeadStraws             );
       AUX_VARIABLE( numberOfTRTTubeHits               );
       AUX_VARIABLE( numberOfTRTXenonHits              );
-
+      AUX_VARIABLE( numberOfTRTSharedHits              );
       AUX_VARIABLE( numberOfPrecisionLayers );
       AUX_VARIABLE( numberOfPrecisionHoleLayers );
       AUX_VARIABLE( numberOfPhiLayers );
diff --git a/Event/xAOD/xAODTracking/Root/TrackParticle_v1.cxx b/Event/xAOD/xAODTracking/Root/TrackParticle_v1.cxx
index 9261d3e013dddd3b5d4f9ebd65c6dcb89f5bcc31..bfa20fbe1d36b83dc55d3b7f59caf11a21e580ab 100644
--- a/Event/xAOD/xAODTracking/Root/TrackParticle_v1.cxx
+++ b/Event/xAOD/xAODTracking/Root/TrackParticle_v1.cxx
@@ -246,6 +246,7 @@ namespace xAOD {
   size_t TrackParticle_v1::numberOfParameters() const{
     ///@todo - Can we do this in a better way? Not great to force retrieval of one specific parameter - any would do.
     static Accessor< std::vector<float>  > acc( "parameterX" );
+    if(! acc.isAvailable( *this )) return 0;
     return acc(*this).size();
   }
 
diff --git a/Event/xAOD/xAODTracking/Root/TrackSummaryAccessors_v1.cxx b/Event/xAOD/xAODTracking/Root/TrackSummaryAccessors_v1.cxx
index 2bfb84d53bd84b466e38650fe51fb701737c729b..edffa020f373a2aa0d088a5285353bdd50e358b9 100644
--- a/Event/xAOD/xAODTracking/Root/TrackSummaryAccessors_v1.cxx
+++ b/Event/xAOD/xAODTracking/Root/TrackSummaryAccessors_v1.cxx
@@ -95,6 +95,7 @@ namespace xAOD {
         DEFINE_ACCESSOR( uint8_t, numberOfTRTDeadStraws             );
         DEFINE_ACCESSOR( uint8_t, numberOfTRTTubeHits               );
         DEFINE_ACCESSOR( uint8_t, numberOfTRTXenonHits              );
+	DEFINE_ACCESSOR( uint8_t, numberOfTRTSharedHits              );
         DEFINE_ACCESSOR( uint8_t, numberOfPrecisionLayers );
         DEFINE_ACCESSOR( uint8_t, numberOfPrecisionHoleLayers );
         DEFINE_ACCESSOR( uint8_t, numberOfPhiLayers );
diff --git a/Event/xAOD/xAODTracking/xAODTracking/TrackingPrimitives.h b/Event/xAOD/xAODTracking/xAODTracking/TrackingPrimitives.h
index 118e1d37491736ecbceb4ae931e879ebe53481c6..ed2aba54f382ac9d2f17309fbf2b3f5ce628989d 100644
--- a/Event/xAOD/xAODTracking/xAODTracking/TrackingPrimitives.h
+++ b/Event/xAOD/xAODTracking/xAODTracking/TrackingPrimitives.h
@@ -258,6 +258,7 @@ namespace xAOD {
     numberOfTRTDeadStraws           =37,  //!< number of dead TRT straws crossed [unit8_t].
     numberOfTRTTubeHits             =38,  //!< number of TRT tube hits [unit8_t].
     numberOfTRTXenonHits            =46,  //!< number of TRT hits on track in straws with xenon [unit8_t].
+    numberOfTRTSharedHits           =62,  //!< number of TRT hits used by more than one track
 
     // --- Muon Spectrometer
     numberOfPrecisionLayers = 7,       //!< layers with at least 3 hits [unit8_t].
@@ -277,7 +278,7 @@ namespace xAOD {
     eProbabilityBrem                = 50, //!< Electron probability from Brem fitting (DNA) [float].  
     pixeldEdx                       = 51, //!< the dE/dx estimate, calculated using the pixel clusters [?]
     // -- numbers...
-    numberOfTrackSummaryTypes       = 62
+    numberOfTrackSummaryTypes       = 63
   };
 
   /// Enumerates the different types of information stored in Summary. 
diff --git a/Event/xAOD/xAODTracking/xAODTracking/versions/TrackParticleAuxContainer_v2.h b/Event/xAOD/xAODTracking/xAODTracking/versions/TrackParticleAuxContainer_v2.h
index e976cd4df6e01928de71b5404340ad4bd2715c0f..64e81a6ac3b7200de6435dc8e27d7e29e5e16fc2 100644
--- a/Event/xAOD/xAODTracking/xAODTracking/versions/TrackParticleAuxContainer_v2.h
+++ b/Event/xAOD/xAODTracking/xAODTracking/versions/TrackParticleAuxContainer_v2.h
@@ -134,6 +134,7 @@ namespace xAOD {
      std::vector< uint8_t >         numberOfTRTDeadStraws            ;
      std::vector< uint8_t >         numberOfTRTTubeHits              ;
      std::vector< uint8_t >         numberOfTRTXenonHits             ;
+     std::vector< uint8_t >         numberOfTRTSharedHits             ;
      
      std::vector< uint8_t >         numberOfPrecisionLayers;
      std::vector< uint8_t >         numberOfPrecisionHoleLayers;