diff --git a/unix/mphalport.h b/unix/mphalport.h
index 9e232c5609..00e79ec17c 100644
--- a/unix/mphalport.h
+++ b/unix/mphalport.h
@@ -38,6 +38,7 @@ void mp_hal_stdio_mode_orig(void);
 // "The useconds argument shall be less than one million."
 static inline void mp_hal_delay_ms(mp_uint_t ms) { usleep((ms) * 1000); }
 static inline void mp_hal_delay_us(mp_uint_t us) { usleep(us); }
+#define mp_hal_ticks_cpu() 0
 
 #define RAISE_ERRNO(err_flag, error_val) \
     { if (err_flag == -1) \