diff --git a/src/mesh/tnlTraversal.h b/src/mesh/tnlTraversal.h
index 2bd33dffcda4c13eda3bc2ac0b231d34f3b5e3e9..a43addc3b7875b4ce599ee71f93f30420a4580b8 100644
--- a/src/mesh/tnlTraversal.h
+++ b/src/mesh/tnlTraversal.h
@@ -18,7 +18,9 @@
 #ifndef TNLTRAVERSAL_H_
 #define TNLTRAVERSAL_H_
 
-
+template< typename Mesh,
+          typename UserData >
+class tnlTraversal{};
 
 
 #endif /* TNLTRAVERSAL_H_ */