diff --git a/cpu/native/ng_tapnet/ng_tapnet.c b/cpu/native/ng_tapnet/ng_tapnet.c
index cdfcb2f0341b..3ae1dbc5f529 100644
--- a/cpu/native/ng_tapnet/ng_tapnet.c
+++ b/cpu/native/ng_tapnet/ng_tapnet.c
@@ -100,12 +100,14 @@ const ng_netdev_driver_t ng_tapnet_driver = {
 
 static inline bool _has_src(ng_pktsnip_t *pkt)
 {
-    return (pkt->size != (sizeof(ng_netif_hdr_t) + (2 * NG_ETHERNET_ADDR_LEN)));
+    return ((pkt->size > sizeof(ng_netif_hdr_t)) &&
+            ((ng_netif_hdr_t *)pkt->data)->src_l2addr_len == NG_ETHERNET_ADDR_LEN);
 }
 
 static inline bool _for_ethernet(ng_pktsnip_t *pkt)
 {
-    return ((pkt->size != (sizeof(ng_netif_hdr_t) + NG_ETHERNET_ADDR_LEN)) ||
+    return (((pkt->size == (sizeof(ng_netif_hdr_t)) &&
+              ((ng_netif_hdr_t *)pkt->data)->dst_l2addr_len)) ||
             _has_src(pkt));
 }
 
@@ -629,7 +631,7 @@ static void _rx_event(ng_tapnet_t *dev)
 
         DEBUG("from %02x:%02x:%02x:%02x:%02x:%02x of length %zu\n",
               hdr->src[0], hdr->src[1], hdr->src[2], hdr->src[3], hdr->src[4],
-              hdr->src[5], data_len - ng_netif_hdr_sizeof(pkt->data));
+              hdr->src[5], data_len - ng_netif_hdr_sizeof(netif_hdr->data));
 #if defined(MODULE_OD) && ENABLE_DEBUG
         od_hex_dump(hdr, data_len, OD_WIDTH_DEFAULT);
 #endif