--- kcheckpass/kcheckpass.c.orig	2016-12-20 15:34:56.868688234 +0400
+++ kcheckpass/kcheckpass.c	2016-12-20 15:35:48.092223200 +0400
@@ -45,6 +45,7 @@
  *
  *****************************************************************/
 
+#define _GNU_SOURCE
 #include "kcheckpass.h"
 
 #include <stdarg.h>