Как исправить ошибку '__interrupt' attribute directive ignored [-Wattributes]?

Warning 1 '__interrupt' attribute directive ignored [-Wattributes] C:\Users\Tekri\Documents\Atmel Studio\6.1\GccApplication4\GccApplication4\GccApplication4.c 23 1 GccApplication4

#include <avr/io.h>
#include <stdint.h>
#include <avr/interrupt.h>

#define LED 1
float timer;

int main (void) {
	TCCR0 = 0;
	TCCR0 = (0<<COM01)|(0<<COM00)|(1<<WGM01)|(0<<WGM00);
	TCNT0= 0;
	OCR0 = 1;
	TIFR = (1<<OCIE0);
	TIMSK  = (1<<OCIE0);
	TCCR0 |= (0<<CS02)|(0<<CS01)|(1<<CS00);
	
	 DDRC |= (1<<LED);
	 
	 sei();
	 while(1);
	 return 0;
 }
void TIM0_CTC(void) __attribute__ ((__interrupt (TIMER0_COMP_vect)));
 void TIM0_CTC(void)
 {
timer = timer+0.0625;

if (timer>10000) PORTC  |=(1<<LED);
if (timer >20000) PORTC |= (0<<LED);
if (timer >30000) timer =0;
}