diff --git a/examples/ipv6/slip-radio/project-conf.h b/examples/ipv6/slip-radio/project-conf.h
index c8288f2b6..fc51e55ec 100644
--- a/examples/ipv6/slip-radio/project-conf.h
+++ b/examples/ipv6/slip-radio/project-conf.h
@@ -30,13 +30,10 @@
 #ifndef PROJECT_CONF_H_
 #define PROJECT_CONF_H_
 
-#undef QUEUEBUF_CONF_NUM
 #define QUEUEBUF_CONF_NUM          4
 
-#undef UIP_CONF_BUFFER_SIZE
 #define UIP_CONF_BUFFER_SIZE    140
 
-#undef UIP_CONF_ROUTER
 #define UIP_CONF_ROUTER                 0
 
 #define CMD_CONF_OUTPUT slip_radio_cmd_output
@@ -55,10 +52,8 @@
 /* Configuration for the slipradio/network driver. */
 #define NETSTACK_CONF_NETWORK slipnet_driver
 
-#undef NETSTACK_CONF_FRAMER
 #define NETSTACK_CONF_FRAMER no_framer
 
-#undef UART1_CONF_RX_WITH_DMA
 #define UART1_CONF_RX_WITH_DMA           1
 
 #endif /* PROJECT_CONF_H_ */