Sketch

#include <SPI.h>
#include <Wire.h>
#ifdef __AVR__
#include <avr/power.h>
#endif
void setup() {
  // put your setup code here, to run once:
#if defined (__AVR_ATtiny85__)
  if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
#endif
}

void loop() {
  // put your main code here, to run repeatedly:

}