diff --git a/src/core/netif.c b/src/core/netif.c
index a32101bc..e9627271 100644
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -1057,6 +1057,8 @@ netif_poll(struct netif *netif)
     in_end->next = NULL;
     SYS_ARCH_UNPROTECT(lev);
 
+    in->if_idx = netif_get_index(netif);
+
     LINK_STATS_INC(link.recv);
     MIB2_STATS_NETIF_ADD(stats_if, ifinoctets, in->tot_len);
     MIB2_STATS_NETIF_INC(stats_if, ifinucastpkts);