diff --git a/libraries/AP_Networking/AP_Networking_ChibiOS.cpp b/libraries/AP_Networking/AP_Networking_ChibiOS.cpp
index ea5e4f42a6b0e1..ccc60ab0dfecf2 100644
--- a/libraries/AP_Networking/AP_Networking_ChibiOS.cpp
+++ b/libraries/AP_Networking/AP_Networking_ChibiOS.cpp
@@ -6,7 +6,6 @@
 #include "AP_Networking_ChibiOS.h"
 #include <GCS_MAVLink/GCS.h>
 
-#include <lwipthread.h>
 #include <lwip/udp.h>
 #include <lwip/ip_addr.h>
 
diff --git a/libraries/AP_Networking/AP_Networking_PPP.cpp b/libraries/AP_Networking/AP_Networking_PPP.cpp
index 1eb886d77c6210..c1f8ecaa76065b 100644
--- a/libraries/AP_Networking/AP_Networking_PPP.cpp
+++ b/libraries/AP_Networking/AP_Networking_PPP.cpp
@@ -12,6 +12,7 @@
 #include <netif/ppp/pppapi.h>
 #include <netif/ppp/pppos.h>
 #include <lwip/tcpip.h>
+#include <stdio.h>
 
 
 extern const AP_HAL::HAL& hal;
@@ -32,7 +33,7 @@ uint32_t AP_Networking_PPP::ppp_output_cb(ppp_pcb *pcb, const void *data, uint32
     auto &driver = *(AP_Networking_PPP *)ctx;
     LWIP_UNUSED_ARG(pcb);
     uint32_t remaining = len;
-    uint8_t *ptr = const_cast<uint8_t*>((const uint8_t *)data);
+    const uint8_t *ptr = (const uint8_t *)data;
     while (remaining > 0) {
         auto n = driver.uart->write(ptr, remaining);
         if (n > 0) {
@@ -122,7 +123,8 @@ void AP_Networking_PPP::ppp_status_callback(struct ppp_pcb_s *pcb, int code, voi
  */
 bool AP_Networking_PPP::init()
 {
-    uart = AP::serialmanager().find_serial(AP_SerialManager::SerialProtocol_PPP, 0);
+    auto &sm = AP::serialmanager();
+    uart = sm.find_serial(AP_SerialManager::SerialProtocol_PPP, 0);
     if (uart == nullptr) {
         return false;
     }
diff --git a/libraries/AP_Networking/config/lwipopts.h b/libraries/AP_Networking/config/lwipopts.h
index a2a516e91349fd..5c65b49f88fb56 100644
--- a/libraries/AP_Networking/config/lwipopts.h
+++ b/libraries/AP_Networking/config/lwipopts.h
@@ -88,6 +88,9 @@ extern "C"
 #define LWIP_TIMEVAL_PRIVATE 0
 #define LWIP_FD_SET_PRIVATE 0
 
+#define TCP_WND 12000
+#define TCP_SND_BUF 12000
+    
 // #define LWIP_DEBUG
 #ifdef LWIP_DEBUG
 #define LWIP_DBG_MIN_LEVEL         0
@@ -204,7 +207,9 @@ a lot of data that needs to be copied, this should be set high. */
 #define TCP_MSS                 1024
 
 /* TCP sender buffer space (bytes). */
+#ifndef TCP_SND_BUF
 #define TCP_SND_BUF             2048
+#endif
 
 /* TCP sender buffer space (pbufs). This must be at least = 2 *
    TCP_SND_BUF/TCP_MSS for things to work. */
@@ -216,7 +221,9 @@ a lot of data that needs to be copied, this should be set high. */
 #define TCP_SNDLOWAT           (TCP_SND_BUF/2)
 
 /* TCP receive window. */
+#ifndef TCP_WND
 #define TCP_WND                 (20 * 1024)
+#endif
 
 /* Maximum number of retransmissions of data segments. */
 #define TCP_MAXRTX              12