diff --git a/src/apps/altcp_tls/altcp_tls_mbedtls.c b/src/apps/altcp_tls/altcp_tls_mbedtls.c
index 853ed7ce..44fb85d4 100644
--- a/src/apps/altcp_tls/altcp_tls_mbedtls.c
+++ b/src/apps/altcp_tls/altcp_tls_mbedtls.c
@@ -459,10 +459,8 @@ altcp_mbedtls_bio_recv(void *ctx, unsigned char *buf, size_t len)
     }
     return MBEDTLS_ERR_SSL_WANT_READ;
   }
-  /* limit number of bytes to copy to fit into an s16_t for pbuf_header */
-  copy_len = (u16_t)LWIP_MIN(len, 0x7FFF);
   /* limit number of bytes again to copy from first pbuf in a chain only */
-  copy_len = LWIP_MIN(copy_len, p->len);
+  copy_len = (u16_t)LWIP_MIN(len, p->len);
   /* copy the data */
   ret = pbuf_copy_partial(p, buf, copy_len, 0);
   LWIP_ASSERT("ret == copy_len", ret == copy_len);
diff --git a/src/apps/lwiperf/lwiperf.c b/src/apps/lwiperf/lwiperf.c
index a5db43d4..b8d884ad 100644
--- a/src/apps/lwiperf/lwiperf.c
+++ b/src/apps/lwiperf/lwiperf.c
@@ -472,7 +472,7 @@ lwiperf_tcp_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
     }
     conn->next_num = 4; /* 24 bytes received... */
     tmp = pbuf_remove_header(p, 24);
-    LWIP_ASSERT("pbuf_header failed", tmp == 0);
+    LWIP_ASSERT("pbuf_remove_header failed", tmp == 0);
   }
 
   packet_idx = 0;
diff --git a/src/core/pbuf.c b/src/core/pbuf.c
index 0a2d29d2..90b774c5 100644
--- a/src/core/pbuf.c
+++ b/src/core/pbuf.c
@@ -495,7 +495,7 @@ pbuf_add_header_impl(struct pbuf *p, size_t header_size_increment, u8_t force)
     /* boundary check fails? */
     if ((u8_t *)payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) {
       LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE,
-        ("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
+        ("pbuf_add_header: failed as %p < %p (not enough space for new header size)\n",
         (void *)payload, (void *)((u8_t *)p + SIZEOF_STRUCT_PBUF)));
       /* bail out unsuccessfully */
       return 1;
@@ -511,7 +511,7 @@ pbuf_add_header_impl(struct pbuf *p, size_t header_size_increment, u8_t force)
       return 1;
     }
   }
-  LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"U16_F")\n",
+  LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_add_header: old %p new %p (%"U16_F")\n",
     (void *)p->payload, (void *)payload, increment_magnitude));
 
   /* modify pbuf fields */
@@ -605,7 +605,7 @@ pbuf_remove_header(struct pbuf *p, size_t header_size_decrement)
   p->len = (u16_t)(p->len - increment_magnitude);
   p->tot_len = (u16_t)(p->tot_len - increment_magnitude);
 
-  LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"U16_F")\n",
+  LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_remove_header: old %p new %p (%"U16_F")\n",
     (void *)payload, (void *)p->payload, increment_magnitude));
 
   return 0;
diff --git a/src/core/udp.c b/src/core/udp.c
index d9c725de..d2d80d37 100644
--- a/src/core/udp.c
+++ b/src/core/udp.c
@@ -344,7 +344,7 @@ udp_input(struct pbuf *p, struct netif *inp)
 #endif /* CHECKSUM_CHECK_UDP */
     if (pbuf_remove_header(p, UDP_HLEN)) {
       /* Can we cope with this failing? Just assert for now */
-      LWIP_ASSERT("pbuf_header failed\n", 0);
+      LWIP_ASSERT("pbuf_remove_header failed\n", 0);
       UDP_STATS_INC(udp.drop);
       MIB2_STATS_INC(mib2.udpinerrors);
       pbuf_free(p);
diff --git a/src/netif/ppp/mppe.c b/src/netif/ppp/mppe.c
index e546f7cd..a6197969 100644
--- a/src/netif/ppp/mppe.c
+++ b/src/netif/ppp/mppe.c
@@ -257,7 +257,7 @@ mppe_compress(ppp_pcb *pcb, ppp_mppe_state *state, struct pbuf **pb, u16_t proto
 	}
 
 	/* Reveal MPPE header */
-	pbuf_header(np, (s16_t)MPPE_OVHD);
+	pbuf_add_header(np, MPPE_OVHD);
 
 	return ERR_OK;
 }
diff --git a/src/netif/ppp/ppp.c b/src/netif/ppp/ppp.c
index 87e278ea..66470bc4 100644
--- a/src/netif/ppp/ppp.c
+++ b/src/netif/ppp/ppp.c
@@ -957,7 +957,7 @@ void ppp_input(ppp_pcb *pcb, struct pbuf *pb) {
 #endif /* PPP_PROTOCOLNAME */
         ppp_warn("Unsupported protocol 0x%x received", protocol);
 #endif /* PPP_DEBUG */
-        pbuf_header(pb, (s16_t)sizeof(protocol));
+        pbuf_add_header(pb, sizeof(protocol));
         lcp_sprotrej(pcb, (u8_t*)pb->payload, pb->len);
       }
       break;
diff --git a/src/netif/ppp/pppoe.c b/src/netif/ppp/pppoe.c
index ba21913e..05d4b355 100644
--- a/src/netif/ppp/pppoe.c
+++ b/src/netif/ppp/pppoe.c
@@ -662,7 +662,7 @@ pppoe_data_input(struct netif *netif, struct pbuf *pb)
 #endif
   if (pbuf_remove_header(pb, sizeof(struct eth_hdr)) != 0) {
     /* bail out */
-    PPPDEBUG(LOG_ERR, ("pppoe_data_input: pbuf_header failed\n"));
+    PPPDEBUG(LOG_ERR, ("pppoe_data_input: pbuf_remove_header failed\n"));
     LINK_STATS_INC(link.lenerr);
     goto drop;
   } 
@@ -695,7 +695,7 @@ pppoe_data_input(struct netif *netif, struct pbuf *pb)
 
   if (pbuf_remove_header(pb, PPPOE_HEADERLEN) != 0) {
     /* bail out */
-    PPPDEBUG(LOG_ERR, ("pppoe_data_input: pbuf_header PPPOE_HEADERLEN failed\n"));
+    PPPDEBUG(LOG_ERR, ("pppoe_data_input: pbuf_remove_header PPPOE_HEADERLEN failed\n"));
     LINK_STATS_INC(link.lenerr);
     goto drop;
   } 
@@ -724,7 +724,7 @@ pppoe_output(struct pppoe_softc *sc, struct pbuf *pb)
   err_t res;
 
   /* make room for Ethernet header - should not fail */
-  if (pbuf_header(pb, (s16_t)(sizeof(struct eth_hdr))) != 0) {
+  if (pbuf_add_header(pb, sizeof(struct eth_hdr)) != 0) {
     /* bail out */
     PPPDEBUG(LOG_ERR, ("pppoe: %c%c%"U16_F": pppoe_output: could not allocate room for Ethernet header\n", sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num));
     LINK_STATS_INC(link.lenerr);
@@ -1043,7 +1043,7 @@ pppoe_send_padt(struct netif *outgoing_if, u_int session, const u8_t *dest)
   }
   LWIP_ASSERT("pb->tot_len == pb->len", pb->tot_len == pb->len);
 
-  pbuf_header(pb, (s16_t)sizeof(struct eth_hdr));
+  pbuf_add_header(pb, sizeof(struct eth_hdr));
   ethhdr = (struct eth_hdr *)pb->payload;
   ethhdr->type = PP_HTONS(ETHTYPE_PPPOEDISC);
   MEMCPY(&ethhdr->dest.addr, dest, sizeof(ethhdr->dest.addr));
@@ -1137,7 +1137,7 @@ pppoe_xmit(struct pppoe_softc *sc, struct pbuf *pb)
   len = pb->tot_len;
 
   /* make room for PPPoE header - should not fail */
-  if (pbuf_header(pb, (s16_t)(PPPOE_HEADERLEN)) != 0) {
+  if (pbuf_add_header(pb, PPPOE_HEADERLEN) != 0) {
     /* bail out */
     PPPDEBUG(LOG_ERR, ("pppoe: %c%c%"U16_F": pppoe_xmit: could not allocate room for PPPoE header\n", sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num));
     LINK_STATS_INC(link.lenerr);
diff --git a/src/netif/ppp/pppol2tp.c b/src/netif/ppp/pppol2tp.c
index d5087f8d..cd497650 100644
--- a/src/netif/ppp/pppol2tp.c
+++ b/src/netif/ppp/pppol2tp.c
@@ -1108,7 +1108,7 @@ static err_t pppol2tp_xmit(pppol2tp_pcb *l2tp, struct pbuf *pb) {
   u8_t *p;
 
   /* make room for L2TP header - should not fail */
-  if (pbuf_header(pb, (s16_t)PPPOL2TP_OUTPUT_DATA_HEADER_LEN) != 0) {
+  if (pbuf_add_header(pb, PPPOL2TP_OUTPUT_DATA_HEADER_LEN) != 0) {
     /* bail out */
     PPPDEBUG(LOG_ERR, ("pppol2tp: pppol2tp_pcb: could not allocate room for L2TP header\n"));
     LINK_STATS_INC(link.lenerr);
diff --git a/src/netif/ppp/pppos.c b/src/netif/ppp/pppos.c
index 06aed761..706bc09b 100644
--- a/src/netif/ppp/pppos.c
+++ b/src/netif/ppp/pppos.c
@@ -705,7 +705,7 @@ static void pppos_input_callback(void *arg) {
 
   ppp = ((struct pppos_input_header*)pb->payload)->ppp;
   if(pbuf_remove_header(pb, sizeof(struct pppos_input_header))) {
-    LWIP_ASSERT("pbuf_header failed\n", 0);
+    LWIP_ASSERT("pbuf_remove_header failed\n", 0);
     goto drop;
   }
 
diff --git a/src/netif/ppp/vj.c b/src/netif/ppp/vj.c
index 73d20376..62dbf54d 100644
--- a/src/netif/ppp/vj.c
+++ b/src/netif/ppp/vj.c
@@ -409,7 +409,7 @@ vj_compress_tcp(struct vjcompress *comp, struct pbuf **pb)
     hlen -= deltaS + 4;
     if (pbuf_remove_header(np, hlen)){
       /* Can we cope with this failing?  Just assert for now */
-      LWIP_ASSERT("pbuf_header failed\n", 0);
+      LWIP_ASSERT("pbuf_remove_header failed\n", 0);
     }
     cp = (u8_t*)np->payload;
     *cp++ = (u8_t)(changes | NEW_C);
@@ -418,7 +418,7 @@ vj_compress_tcp(struct vjcompress *comp, struct pbuf **pb)
     hlen -= deltaS + 3;
     if (pbuf_remove_header(np, hlen)) {
       /* Can we cope with this failing?  Just assert for now */
-      LWIP_ASSERT("pbuf_header failed\n", 0);
+      LWIP_ASSERT("pbuf_remove_header failed\n", 0);
     }
     cp = (u8_t*)np->payload;
     *cp++ = (u8_t)changes;
@@ -621,7 +621,7 @@ vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp)
   /* Remove the compressed header and prepend the uncompressed header. */
   if (pbuf_remove_header(n0, vjlen)) {
     /* Can we cope with this failing?  Just assert for now */
-    LWIP_ASSERT("pbuf_header failed\n", 0);
+    LWIP_ASSERT("pbuf_remove_header failed\n", 0);
     goto bad;
   }
 
@@ -644,7 +644,7 @@ vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp)
 
     if (pbuf_remove_header(np, cs->cs_hlen)) {
       /* Can we cope with this failing?  Just assert for now */
-      LWIP_ASSERT("pbuf_header failed\n", 0);
+      LWIP_ASSERT("pbuf_remove_header failed\n", 0);
       goto bad;
     }