diff --git a/src/api/tcpip.c b/src/api/tcpip.c
index 1740861c..743553a5 100644
--- a/src/api/tcpip.c
+++ b/src/api/tcpip.c
@@ -171,7 +171,9 @@ tcpip_thread_handle_msg(struct tcpip_msg *msg)
 #if !LWIP_TCPIP_CORE_LOCKING_INPUT
     case TCPIP_MSG_INPKT:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: PACKET %p\n", (void *)msg));
-      msg->msg.inp.input_fn(msg->msg.inp.p, msg->msg.inp.netif);
+      if (msg->msg.inp.input_fn(msg->msg.inp.p, msg->msg.inp.netif) != ERR_OK) {
+        pbuf_free(msg->msg.inp.p);
+      }
       memp_free(MEMP_TCPIP_MSG_INPKT, msg);
       break;
 #endif /* !LWIP_TCPIP_CORE_LOCKING_INPUT */
diff --git a/src/include/lwip/netif.h b/src/include/lwip/netif.h
index 59d518c9..fba4fd7d 100644
--- a/src/include/lwip/netif.h
+++ b/src/include/lwip/netif.h
@@ -171,6 +171,9 @@ typedef err_t (*netif_init_fn)(struct netif *netif);
  *
  * @param p The received packet, copied into a pbuf
  * @param inp The netif which received the packet
+ * @return ERR_OK if the packet was handled
+ *         != ERR_OK is the packet was NOT handled, in this case, the caller has
+ *                   to free the pbuf
  */
 typedef err_t (*netif_input_fn)(struct pbuf *p, struct netif *inp);