diff --git a/src/hdf5_array.hpp b/src/hdf5_array.hpp
index 9587189..db75a33 100644
--- a/src/hdf5_array.hpp
+++ b/src/hdf5_array.hpp
@@ -426,7 +426,7 @@ namespace CosmoTool {
 #define CTOOL_HDF5_INSERT_ELEMENT(r, STRUCT, element) \
      { \
        ::CosmoTool::get_hdf5_data_type<BOOST_PP_TUPLE_ELEM(2, 0, element)> t; \
-       position = HOFFSET(STRUCT, BOOST_PP_TUPLE_ELEM(2, 1, element)); \
+       long position = HOFFSET(STRUCT, BOOST_PP_TUPLE_ELEM(2, 1, element)); \
        const char *field_name = BOOST_PP_STRINGIZE(BOOST_PP_TUPLE_ELEM(2, 1, element)); \
        type.insertMember(field_name,  position, t.type()); \
      } 
@@ -439,7 +439,6 @@ namespace CosmoTool { \
   \
       TNAME() : type(sizeof(STRUCT)) \
       {  \
-        long position; \
         BOOST_PP_SEQ_FOR_EACH(CTOOL_HDF5_INSERT_ELEMENT, STRUCT, ATTRIBUTES) \
       }  \
       \
@@ -471,7 +470,6 @@ namespace CosmoTool { \
   \
       TNAME() : type(sizeof(STRUCT)) \
       {  \
-        long position; \
         BOOST_PP_SEQ_FOR_EACH(CTOOL_HDF5_INSERT_ENUM_ELEMENT, STRUCT, ATTRIBUTES) \
       }  \
       \