diff --git a/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.cxx b/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.cxx
index d0810d4f5f9894db3c5db85ae831e1d878a31539..97f3ee44871f3d9376799aceee9cf5ccedcfb57d 100644
--- a/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.cxx
+++ b/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.cxx
@@ -303,9 +303,9 @@ namespace ActsTrk
 
   StatusCode CoreStripSpacePointFormationTool::fillSpacePoints(const EventContext &ctx,
 							       std::shared_ptr<Acts::SpacePointBuilder<StripSP>> spBuilder,
-							       std::array<const InDetDD::SiDetectorElement *,nNeighbours> elements,
-							       std::array<std::vector<std::pair<ATLASUncalibSourceLink, size_t>>,nNeighbours> sourceLinks,
-							       std::array<double, 14> overlapExtents,
+							       const std::array<const InDetDD::SiDetectorElement *,nNeighbours>& elements,
+							       const std::array<std::vector<std::pair<ATLASUncalibSourceLink, size_t>>,nNeighbours>& sourceLinks,
+							       const std::array<double, 14>& overlapExtents,
 							       const Amg::Vector3D &beamSpotVertex,
 							       std::vector<StripSP>& spacePoints,
 							       std::vector<StripSP>& overlapSpacePoints ) const
diff --git a/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.h b/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.h
index 7cf5acf92e7dc7efd4a96e68a3fcc5183e8ce557..fa9a5905f6a0969a5bea6ec897dc0e6832343f63 100644
--- a/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.h
+++ b/Tracking/Acts/ActsDataPreparation/src/CoreStripSpacePointFormationTool.h
@@ -60,9 +60,9 @@ namespace ActsTrk {
 
     StatusCode fillSpacePoints(const EventContext& ctx,
 			      std::shared_ptr<Acts::SpacePointBuilder<StripSP>> spBuilder,
-			      std::array<const InDetDD::SiDetectorElement*,nNeighbours> neighbourElements,
-			      std::array<std::vector<std::pair<ATLASUncalibSourceLink, size_t>>,nNeighbours> neighbourSourceLinks,
-			      std::array<double, 14> overlapExtents,
+			      const std::array<const InDetDD::SiDetectorElement*,nNeighbours>& neighbourElements,
+			      const std::array<std::vector<std::pair<ATLASUncalibSourceLink, size_t>>,nNeighbours>& neighbourSourceLinks,
+			      const std::array<double, 14>& overlapExtents,
 			      const Amg::Vector3D& beamSpotVertex,
 			      std::vector<StripSP>& spacePoints,
 			      std::vector<StripSP>& overlapSpacePoints ) const;