diff --git a/src/netif/bridgeif.c b/src/netif/bridgeif.c
index ec5a29ea..8a97bce3 100644
--- a/src/netif/bridgeif.c
+++ b/src/netif/bridgeif.c
@@ -418,6 +418,7 @@ bridgeif_init(struct netif *netif)
   mem_size_t alloc_len;
 
   LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("bridgeif needs an input callback", (netif->input != NULL));
 #if !BRIDGEIF_PORT_NETIFS_OUTPUT_DIRECT
   if (netif->input == tcpip_input) {
     LWIP_DEBUGF(BRIDGEIF_DEBUG | LWIP_DBG_ON, ("bridgeif does not need tcpip_input, use netif_input/ethernet_input instead"));
diff --git a/src/netif/slipif.c b/src/netif/slipif.c
index fc5fd182..9b175dc3 100644
--- a/src/netif/slipif.c
+++ b/src/netif/slipif.c
@@ -362,6 +362,8 @@ slipif_init(struct netif *netif)
   struct slipif_priv *priv;
   u8_t sio_num;
 
+  LWIP_ASSERT("slipif needs an input callback", netif->input != NULL);
+
   /* netif->state contains serial port number */
   sio_num = LWIP_PTR_NUMERIC_CAST(u8_t, netif->state);
 
diff --git a/src/netif/zepif.c b/src/netif/zepif.c
index 98afbc4c..3f8d59b8 100644
--- a/src/netif/zepif.c
+++ b/src/netif/zepif.c
@@ -224,6 +224,8 @@ zepif_init(struct netif *netif)
   struct zepif_init *init_state = (struct zepif_init *)netif->state;
   struct zepif_state *state = (struct zepif_state *)mem_malloc(sizeof(struct zepif_state));
 
+  LWIP_ASSERT("zepif needs an input callback", netif->input != NULL);
+
   if (state == NULL) {
     return ERR_MEM;
   }