diff --git a/src/core/pbuf.c b/src/core/pbuf.c
index 0ecffd22..39ecda68 100644
--- a/src/core/pbuf.c
+++ b/src/core/pbuf.c
@@ -780,7 +780,7 @@ pbuf_free(struct pbuf *p)
       /* p->ref > 0, this pbuf is still referenced to */
       /* (and so the remaining pbufs in chain as well) */
     } else {
-      LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
+      LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, (u16_t)ref));
       /* stop walking through the chain */
       p = NULL;
     }
diff --git a/src/netif/ethernet.c b/src/netif/ethernet.c
index 3ac2fcef..56f72c8f 100644
--- a/src/netif/ethernet.c
+++ b/src/netif/ethernet.c
@@ -102,10 +102,10 @@ ethernet_input(struct pbuf *p, struct netif *netif)
   ethhdr = (struct eth_hdr *)p->payload;
   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
               ("ethernet_input: dest:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", src:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", type:%"X16_F"\n",
-               (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
-               (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
-               (unsigned)ethhdr->src.addr[0],  (unsigned)ethhdr->src.addr[1],  (unsigned)ethhdr->src.addr[2],
-               (unsigned)ethhdr->src.addr[3],  (unsigned)ethhdr->src.addr[4],  (unsigned)ethhdr->src.addr[5],
+               (unsigned char)ethhdr->dest.addr[0], (unsigned char)ethhdr->dest.addr[1], (unsigned char)ethhdr->dest.addr[2],
+               (unsigned char)ethhdr->dest.addr[3], (unsigned char)ethhdr->dest.addr[4], (unsigned char)ethhdr->dest.addr[5],
+               (unsigned char)ethhdr->src.addr[0],  (unsigned char)ethhdr->src.addr[1],  (unsigned char)ethhdr->src.addr[2],
+               (unsigned char)ethhdr->src.addr[3],  (unsigned char)ethhdr->src.addr[4],  (unsigned char)ethhdr->src.addr[5],
                lwip_htons(ethhdr->type)));
 
   type = ethhdr->type;
diff --git a/test/unit/tcp/test_tcp.c b/test/unit/tcp/test_tcp.c
index c272202c..ba89cd6d 100644
--- a/test/unit/tcp/test_tcp.c
+++ b/test/unit/tcp/test_tcp.c
@@ -263,7 +263,6 @@ test_tcp_recv_expectclose(void* arg, struct tcp_pcb* pcb, struct pbuf* p, err_t
 
   if (p != NULL) {
     fail();
-    pbuf_free(p);
   } else {
     /* correct: FIN received; close our end, too */
     err_t err2 = tcp_close(pcb);