diff --git a/CMakeLists.txt b/CMakeLists.txt
index ef6e9ba969566da6e6451bb0aa510bc81fd983b4..934ebf555fca7c08b9b8104ee2b4aee6e83705e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -56,6 +56,7 @@ include( DD4hepMacros )
 #-----------------------------
 
 find_package(ROOT REQUIRED)
+include_directories( SYSTEM ${ROOT_INCLUDE_DIR} )
 
 ##checks for xercesc or not and sets up the include_directories
 include(DD4hep_XML_setup)
@@ -131,6 +132,7 @@ if(DD4HEP_USE_GEANT4)
     endif()
 
     find_package( CLHEP REQUIRED )
+    include_directories( SYSTEM ${CLHEP_INCLUDE_DIRS} )
 
     get_filename_component(CLHEP_LIBRARY_PATH "${CLHEP_LIBRARIES}" PATH)