-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h> /* Prototypes for lseek, sbrk (maybe) */
+#define _GNU_SOURCE
+#include "src/internal_config.h"
+#if HAVE_UNISTD_H
+#include <unistd.h> /* Prototypes for lseek, sbrk (maybe) */