Atmega328p Watchdog

Hello!
Pro Mini Atmega328p 16MHz 5V
Erase chip:
avrdude -cstk500v1 -patmega328p -PCOM7 -e -b19200
Write fuse:
avrdude -cstk500v1 -patmega328p -PCOM7 -b19200 -U lfuse:w:0xff:m -U hfuse:w:0xdf:m -U efuse:w:0x05:m
Write scketch:

#include <avr/wdt.h>

void setup() {
  wdt_disable();
  // put your setup code here, to run once:
digitalWrite(13,1);
delay(3000);
wdt_enable(WDTO_4S);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(13,0);
delay(1000);
digitalWrite(13,1);
delay(500);
}

The board doesn’t reboot.
Crazy blink led13.
Why?

Most likely the problem is that your pro-mini is using a older bootloader that does not handle WDT interrupts correctly. Best solution if you wish to utilize WDT is to load the current Uno bootloader to your pro-mini and thereafter select & treat it as a Uno board and WDT functions will work correctly.

Thank you!
My Pro Mini bootloader less.
I found the solution of this problem.

setup(){
 MCUSR = 0
 wdt_disable();
.....
}