--- a/lib/tty/tty-ncurses.h
+++ b/lib/tty/tty-ncurses.h
@@ -3,6 +3,7 @@
 #define MC__TTY_NCURSES_H
 
 #ifdef USE_NCURSES
+#define _XOPEN_SOURCE_EXTENDED
 #ifdef HAVE_NCURSES_CURSES_H
 #include <ncurses/curses.h>
 #elif defined (HAVE_NCURSES_NCURSES_H)