diff --git a/DDRec/include/DDRec/MaterialManager.h b/DDRec/include/DDRec/MaterialManager.h
index 4d033da8213a45d64dad8684c3fcafa79886ce69..688861bc3510b1d9c4173ad75c5fac7cca2c5310 100644
--- a/DDRec/include/DDRec/MaterialManager.h
+++ b/DDRec/include/DDRec/MaterialManager.h
@@ -14,7 +14,8 @@ class TGeoManager ;
 namespace DD4hep {
   namespace DDRec {
 
-    typedef Geometry::Material Material ;
+    //  export Geometry::Material to this namespace ;
+    using  Geometry::Material ;
 
     typedef std::vector< std::pair< Material, double > > MaterialVec ;