* Interrupt routing for I2C. Refer to datasheets for more
* informations.
*/
-#if !defined(TWI_vect) && defined(SIG_2WIRE_SERIAL)
+#ifndef TWI_vect
+#if defined(SIG_2WIRE_SERIAL)
#define TWI_vect SIG_2WIRE_SERIAL
#endif
+#endif
SIGNAL(TWI_vect)
{
uint8_t hard_status;