diff --git a/platform/avr-atmega128rfa1/Makefile.avr-atmega128rfa1 b/platform/avr-atmega128rfa1/Makefile.avr-atmega128rfa1
index 9e8b7ea75..d845dd61f 100644
--- a/platform/avr-atmega128rfa1/Makefile.avr-atmega128rfa1
+++ b/platform/avr-atmega128rfa1/Makefile.avr-atmega128rfa1
@@ -3,6 +3,8 @@ CONTIKI_TARGET_DIRS = . apps net loader
 CONTIKI_CORE=contiki-main
 CONTIKI_TARGET_MAIN = ${CONTIKI_CORE}.o
 CONTIKI_TARGET_SOURCEFILES += contiki-main.c
+#Needed for slip
+CONTIKI_TARGET_SOURCEFILES += button-sensor.c sensors.c slip_uart0.c slip.c
 
 CONTIKIAVR=$(CONTIKI)/cpu/avr
 CONTIKIBOARD=.