diff --git a/unittest/user_type.cpp b/unittest/user_type.cpp
index b128648a3bb33174c9564b339f227e43300bb3ff..a6fdeee89031774403abbd52537aa1bf2ab80b30 100644
--- a/unittest/user_type.cpp
+++ b/unittest/user_type.cpp
@@ -89,7 +89,8 @@ void expose_custom_type(const std::string & name)
   .def("__repr__",&Type::print)
   ;
   
-  eigenpy::registerNewType<Type>();
+  int code = eigenpy::registerNewType<Type>();
+  std::cout << "code: " << code << std::endl;
   eigenpy::registerCommonUfunc<Type>();
 }