diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index 331b2cc917ec..af56d27693d0 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -580,6 +580,8 @@ static void item_add_str(const char *fmt, ...)
 		tmp_str,
 		sizeof(k_menu_items[index].str));
 
+	k_menu_items[index].str[sizeof(k_menu_items[index].str) - 1] = '\0';
+
 	free_item(curses_menu_items[index]);
 	curses_menu_items[index] = new_item(
 			k_menu_items[index].str,
diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index 77f525a8617c..8b3e9bc893a7 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/scripts/kconfig/nconf.gui.c
@@ -398,6 +398,7 @@ int dialog_inputbox(WINDOW *main_window,
 	x = (columns-win_cols)/2;
 
 	strncpy(result, init, *result_len);
+	result[*result_len - 1] = '\0';
 
 	/* create the windows */
 	win = newwin(win_lines, win_cols, y, x);