diff --git a/unix/mphalport.h b/unix/mphalport.h
index 9e232c56091d48a821c7c4a9b445187f4a5b1dcf..00e79ec17c7ca6d676ed5a7dd0dd1e22150a965e 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) \