diff --git a/Mesh/periodical.h b/Mesh/periodical.h
index b9020644154ad8cf1ddd081ded2e6a03d8c7bf4e..f5c34b930271a8703c8e36f1c6a842516a9bc261 100644
--- a/Mesh/periodical.h
+++ b/Mesh/periodical.h
@@ -27,6 +27,7 @@ class voroMetal3D{
   void print_geo_face(int,int,std::ofstream&);
   void print_geo_physical_face(int,int,std::ofstream&);
   void print_geo_volume(int,int,std::ofstream&);
+  void print_geo_physical_volume(int,int,std::ofstream&);
   void print_geo_line_loop(int,std::vector<int>&,std::vector<int>&,std::ofstream&);
   void print_geo_face_loop(int,std::vector<int>&,std::ofstream&);
   void correspondance(double);