diff --git a/net/ip/contiki/ip/tcpip.c b/net/ip/contiki/ip/tcpip.c
index 7ae49bdf9d4..f637f807f06 100644
--- a/net/ip/contiki/ip/tcpip.c
+++ b/net/ip/contiki/ip/tcpip.c
@@ -535,12 +535,7 @@ eventhandler(process_event_t ev, process_data_t data, struct net_buf *buf)
 #endif /* UIP_UDP */
 
     case PACKET_INPUT:
-      if (!packet_input(buf)) {
-         /* failure, discard the net_buf here because the
-          * return value cannot be passed to driver any longer
-          */
-         net_buf_put(buf);
-      }
+      packet_input(buf);
       break;
   };
 }
diff --git a/net/ip/contiki/ipv6/uip6.c b/net/ip/contiki/ipv6/uip6.c
index f3029a62ed2..4840251b6c3 100644
--- a/net/ip/contiki/ipv6/uip6.c
+++ b/net/ip/contiki/ipv6/uip6.c
@@ -1545,6 +1545,7 @@ uip_process(struct net_buf *buf, uint8_t flag)
   uip_icmp6_error_output(buf, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
   goto send;
 #else
+  uip_len(buf) = 0;
   goto drop;
 #endif
 
diff --git a/net/ip/net_init.c b/net/ip/net_init.c
index 6cf87021adb..e30d688fb04 100644
--- a/net/ip/net_init.c
+++ b/net/ip/net_init.c
@@ -347,15 +347,12 @@ static void net_rx_fiber(void)
 	NET_DBG("Starting RX fiber\n");
 
 	while (1) {
-		/* Wait next packet from network */
 		buf = nano_fifo_get_wait(&netdev.rx_queue);
 
 		/* Check stack usage (no-op if not enabled) */
 		analyze_stacks(buf, &buf);
 
-		/* TBD: Pass it to IP stack */
-
-		net_buf_put(buf);
+		tcpip_input(buf);
 	}
 }