diff --git a/Tracking/TrkDetDescr/TrkDetDescrAlgs/CMakeLists.txt b/Tracking/TrkDetDescr/TrkDetDescrAlgs/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..5fde413840f5c7bd556bd9f3223f0a3a6f0a0cb2
--- /dev/null
+++ b/Tracking/TrkDetDescr/TrkDetDescrAlgs/CMakeLists.txt
@@ -0,0 +1,36 @@
+################################################################################
+# Package: TrkDetDescrAlgs
+################################################################################
+
+# Declare the package name:
+atlas_subdir( TrkDetDescrAlgs )
+
+# Declare the package's dependencies:
+atlas_depends_on_subdirs( PUBLIC
+                          Control/AthenaBaseComps
+                          DetectorDescription/GeoPrimitives
+                          GaudiKernel
+                          Tracking/TrkDetDescr/TrkDetDescrUtils
+                          PRIVATE
+                          Tracking/TrkDetDescr/TrkDetDescrInterfaces
+                          Tracking/TrkDetDescr/TrkGeometry
+                          Tracking/TrkDetDescr/TrkVolumes
+                          Tracking/TrkEvent/TrkNeutralParameters
+                          Tracking/TrkExtrapolation/TrkExInterfaces )
+
+# External dependencies:
+find_package( Eigen )
+find_package( ROOT COMPONENTS Core Tree MathCore Hist RIO pthread )
+
+# tag use_trkdetdescr_memmon was not recognized in automatic conversion in cmt2cmake
+
+# Component(s) in the package:
+atlas_add_component( TrkDetDescrAlgs
+                     src/*.cxx
+                     src/components/*.cxx
+                     INCLUDE_DIRS ${ROOT_INCLUDE_DIRS} ${EIGEN_INCLUDE_DIRS}
+                     LINK_LIBRARIES ${ROOT_LIBRARIES} ${EIGEN_LIBRARIES} AthenaBaseComps GeoPrimitives GaudiKernel TrkDetDescrUtils TrkDetDescrInterfaces TrkGeometry TrkVolumes TrkNeutralParameters TrkExInterfaces )
+
+# Install files from the package:
+atlas_install_headers( TrkDetDescrAlgs )
+
diff --git a/Tracking/TrkDetDescr/TrkDetDescrAlgs/src/MaterialMapping.cxx b/Tracking/TrkDetDescr/TrkDetDescrAlgs/src/MaterialMapping.cxx
index 1d81e509f74f23e139ccbaf6f3c17ca0ba2a430a..81917cfa31d4465ba0a3e57a2407630bec48aea5 100755
--- a/Tracking/TrkDetDescr/TrkDetDescrAlgs/src/MaterialMapping.cxx
+++ b/Tracking/TrkDetDescr/TrkDetDescrAlgs/src/MaterialMapping.cxx
@@ -62,6 +62,7 @@ Trk::MaterialMapping::MaterialMapping(const std::string& name, ISvcLocator* pSvc
   m_elementTable(0),
   m_inputEventElementTable("ElementTable"),
   m_accumulatedMaterialXX0(0.),
+  m_accumulatedRhoS(0.),
   m_mapped(0),
   m_unmapped(0),
   m_skippedOutside(0),