diff --git a/platform/avr-ravenusb/fakeuip.c b/platform/avr-ravenusb/fakeuip.c
index 5acaf966c..fe273a756 100644
--- a/platform/avr-ravenusb/fakeuip.c
+++ b/platform/avr-ravenusb/fakeuip.c
@@ -17,7 +17,8 @@ struct uip_stats uip_stat;
 
 uip_lladdr_t uip_lladdr;
 
-u8_t (* tcpip_output)(uip_lladdr_t *);
+u8_t tcpip_output(uip_lladdr_t * lladdr){ return 0; }
+void tcpip_set_outputfunc(u8_t (* f)(uip_lladdr_t *)) { return; }
 
 u16_t htons(u16_t val) { return HTONS(val);}