https://bugs.gentoo.org/885885
--- a/parse.c
+++ b/parse.c
@@ -15,7 +15,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 700
 #include <unistd.h>
 #include <crypt.h>
 #include <stdio.h>
--- a/parseldif.c
+++ b/parseldif.c
@@ -15,7 +15,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-#define _XOPEN_SOURCE
+#define _XOPEN_SOURCE 700
 #include <unistd.h>
 #include <stdio.h>
 #include "common.h"