diff --git a/InnerDetector/InDetCosmics/TRT_SegmentsToTrack/src/TRT_SegmentsToTrack.cxx b/InnerDetector/InDetCosmics/TRT_SegmentsToTrack/src/TRT_SegmentsToTrack.cxx
index fb299cbad40c97c89970493bb966f51fa9a2a7fe..7a1fce3668691b713c119fc61bd0fe95323a8d09 100755
--- a/InnerDetector/InDetCosmics/TRT_SegmentsToTrack/src/TRT_SegmentsToTrack.cxx
+++ b/InnerDetector/InDetCosmics/TRT_SegmentsToTrack/src/TRT_SegmentsToTrack.cxx
@@ -263,6 +263,7 @@ StatusCode InDet::TRT_SegmentsToTrack::execute()
         }
         else {
           auto trajectory = Trk::TrackStateOnSurfaceProtContainer::make_unique();
+          trajectory->reserve (fittedTrack->trackStateOnSurfaces()->size() + 1);
           itSet = fittedTrack->trackStateOnSurfaces()->begin();
           for ( ; itSet!=itSetEnd; ++itSet) {
             if (!(**itSet).type(Trk::TrackStateOnSurface::Perigee)) {
diff --git a/InnerDetector/InDetValidation/InDetTrackSplitterTool/src/InDetTrackSplitterTool.cxx b/InnerDetector/InDetValidation/InDetTrackSplitterTool/src/InDetTrackSplitterTool.cxx
index bdfb93839941926ce1891b5eb309c6fb3fc0f4f9..0f405d594463fe7434f39e24ea4afca0e831fa26 100644
--- a/InnerDetector/InDetValidation/InDetTrackSplitterTool/src/InDetTrackSplitterTool.cxx
+++ b/InnerDetector/InDetValidation/InDetTrackSplitterTool/src/InDetTrackSplitterTool.cxx
@@ -158,7 +158,9 @@ std::pair<Trk::Track*, Trk::Track*> InDet::InDetTrackSplitterTool::splitInUpperL
   /** Get the  measurements */
   auto uppertraj = Trk::TrackStateOnSurfaceProtContainer::make_unique();
   auto lowertraj = Trk::TrackStateOnSurfaceProtContainer::make_unique();
-  
+  uppertraj->reserve (input.trackStateOnSurfaces()->size());
+  lowertraj->reserve (input.trackStateOnSurfaces()->size());
+
   unsigned int totalNumberHits = 0;
 
   unsigned int totalNumberPixelHits = 0;
diff --git a/InnerDetector/InDetValidation/InDetTrackValidation/src/HoleSearchValidation.cxx b/InnerDetector/InDetValidation/InDetTrackValidation/src/HoleSearchValidation.cxx
index 2241734655aaf571923b66a65c422e245b9e2013..81633e32bd03dccd74dabaa60fd78adc4155e7fd 100755
--- a/InnerDetector/InDetValidation/InDetTrackValidation/src/HoleSearchValidation.cxx
+++ b/InnerDetector/InDetValidation/InDetTrackValidation/src/HoleSearchValidation.cxx
@@ -189,6 +189,7 @@ StatusCode HoleSearchValidation::execute(const EventContext& ctx) const {
     unsigned int oldHoles = doHoleSearch( *trackIterator );
 
     auto vecTsos = Trk::TrackStateOnSurfaceProtContainer::make_unique();
+    vecTsos->reserve (tsos->size());
 
     // loop over TSOS, copy TSOS and push into vector
     DataVector<const Trk::TrackStateOnSurface>::const_iterator iTsos    = tsos->begin();