include stddef.h

Include/structmember.h

@@ -30,6 +30,10 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 /* Interface to map C struct members to Python object attributes */
 
+#ifdef HAVE_STDDEF_H
+#include <stddef.h> /* For offsetof */
+#endif
+
 /* The offsetof() macro calculates the offset of a structure member
    in its structure.  Unfortunately this cannot be written down
    portably, hence it is provided by a Standard C header file.