diff --git a/sample/testHDF5.cpp b/sample/testHDF5.cpp
index d38eb01..f09147d 100644
--- a/sample/testHDF5.cpp
+++ b/sample/testHDF5.cpp
@@ -38,10 +38,24 @@ knowledge of the CeCILL license and that you accept its terms.
 
 using namespace std;
 
+struct MyStruct
+{
+  int a;
+  double b;
+  char c;
+};
+
+CTOOL_STRUCT_TYPE(MyStruct, hdf5t_MyStruct,
+    ((int, a))
+    ((double, b))
+    ((char, c))
+)
+
 int main()
 {
   typedef  boost::multi_array<float, 2> array_type;
   typedef  boost::multi_array<float, 3> array3_type;
+  typedef  boost::multi_array<MyStruct, 1> array_mys_type;
   typedef  boost::multi_array<std::complex<double>, 2> arrayc_type;
   typedef array_type::index index;
 
@@ -53,13 +67,23 @@ int main()
   array_type B;
   array3_type C(boost::extents[2][3][4]);
   arrayc_type D, E;
+  array_mys_type F(boost::extents[10]), G;
   
   int values = 0;
   for (index i = 0; i != 2; i++)
     for (index j = 0; j != 3; j++)
       A[i][j] = values++;
       
+  for (index i = 0; i != 10; i++)
+    {
+        F[i].a = i;
+        F[i].b = double(i)/4.;
+        F[i].c = 'r'+i;
+    } 
+  std::cout << " c = " << ((char *)&F[1])[offsetof(MyStruct, c)] << endl;
+    
   CosmoTool::hdf5_write_array(g, "test_data", A);
+  CosmoTool::hdf5_write_array(g, "test_struct", F);
   
   CosmoTool::hdf5_read_array(g, "test_data", B);
 
@@ -95,5 +119,12 @@ int main()
         abort();
       }
 
+  CosmoTool::hdf5_read_array(g, "test_struct", G);
+  for (index i = 0; i != 10; i++)
+    if (G[i].a != F[i].a || G[i].b != F[i].b || G[i].c != F[i].c) {
+        std::cout << "Invalid struct content" << endl;
+        abort();
+    }
+
   return 0;
 }
diff --git a/src/hdf5_array.hpp b/src/hdf5_array.hpp
index fc1a727..2dad3ad 100644
--- a/src/hdf5_array.hpp
+++ b/src/hdf5_array.hpp
@@ -210,31 +210,32 @@ namespace CosmoTool {
 #define CTOOL_HDF5_INSERT_ELEMENT(r, STRUCT, element) \
      { \
        CosmoTool::get_hdf5_data_type<BOOST_PP_TUPLE_ELEM(2, 0, element)> t; \
-       position = offsetof(STRUCT, BOOST_PP_TUPLE_ELEM(2, 1, element)); \
-       type.insertMember(BOOST_PP_STRINGIZE(BOOST_PP_TUPLE_ELEM(2, 1, element)),  position, t.type()); \
+       position = HOFFSET(STRUCT, BOOST_PP_TUPLE_ELEM(2, 1, element)); \
+       const char *field_name = BOOST_PP_STRINGIZE(BOOST_PP_TUPLE_ELEM(2, 1, element)); \
+       std::cout << "Field " << field_name << " offset = " << position << endl; \
+       type.insertMember(field_name,  position, t.type()); \
      } 
   
 #define CTOOL_STRUCT_TYPE(STRUCT, TNAME, ATTRIBUTES) \
 namespace CosmoTool { \
-    class CTOOL_HDF5_NAME(STRUCT) {  \
+    class TNAME {  \
     public:  \
       H5::CompType type;  \
   \
-      CTOOL_HDF5_NAME(STRUCT)() : type(sizeof(STRUCT)) \
+      TNAME() : type(sizeof(STRUCT)) \
       {  \
         long position; \
         BOOST_PP_SEQ_FOR_EACH(CTOOL_HDF5_INSERT_ELEMENT, STRUCT, ATTRIBUTES) \
-        type.pack(); \
       }  \
       \
-      static const CTOOL_HDF5_NAME(STRUCT) *ctype() \
+      static const TNAME *ctype() \
       { \
-        static CTOOL_HDF5_NAME(STRUCT) singleton; \
+        static TNAME singleton; \
         return &singleton; \
       } \
     }; \
     template<> struct get_hdf5_data_type<STRUCT> { \
-        static H5::DataType type() { return CTOOL_HDF5_NAME(STRUCT)::ctype()->type; }; \
+        static H5::DataType type() { return TNAME::ctype()->type; }; \
     }; \
 };