diff --git a/libraries/AP_HAL/utility/Socket.cpp b/libraries/AP_HAL/utility/Socket.cpp
index 363b144d67..0bad1ba6a9 100644
--- a/libraries/AP_HAL/utility/Socket.cpp
+++ b/libraries/AP_HAL/utility/Socket.cpp
@@ -21,9 +21,23 @@
 #if AP_NETWORKING_SOCKETS_ENABLED
 
 #include "Socket.h"
+#if AP_NETWORKING_BACKEND_CHIBIOS || AP_NETWORKING_BACKEND_PPP
+#include <lwip/sockets.h>
+#else
+// SITL or Linux
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <sys/select.h>
+#endif
+
 #include <errno.h>
 
-#if AP_NETWORKING_BACKEND_CHIBIOS
+#if AP_NETWORKING_BACKEND_CHIBIOS || AP_NETWORKING_BACKEND_PPP
 #define CALL_PREFIX(x) ::lwip_##x
 #else
 #define CALL_PREFIX(x) ::x
@@ -33,6 +47,8 @@
 #define MSG_NOSIGNAL 0
 #endif
 
+static_assert(sizeof(last_in_addr) == sizeof(struct sockaddr_in), "last_in_addr must match sockaddr_in size");
+
 /*
   constructor
  */
@@ -185,7 +201,7 @@ bool SocketAPM::connect_timeout(const char *address, uint16_t port, uint32_t tim
     }
     int sock_error = 0;
     socklen_t len = sizeof(sock_error);
-    if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&sock_error, &len) != 0) {
+    if (CALL_PREFIX(getsockopt)(fd, SOL_SOCKET, SO_ERROR, (void*)&sock_error, &len) != 0) {
         return false;
     }
     connected = sock_error == 0;
@@ -294,10 +310,10 @@ ssize_t SocketAPM::recv(void *buf, size_t size, uint32_t timeout_ms)
         errno = EWOULDBLOCK;
         return -1;
     }
-    socklen_t len = sizeof(in_addr);
+    socklen_t len = sizeof(last_in_addr);
     int fin = get_read_fd();
     ssize_t ret;
-    ret = CALL_PREFIX(recvfrom)(fin, buf, size, MSG_DONTWAIT, (sockaddr *)&in_addr, &len);
+    ret = CALL_PREFIX(recvfrom)(fin, buf, size, MSG_DONTWAIT, (sockaddr *)&last_in_addr, &len);
     if (ret <= 0) {
         if (!datagram && connected && ret == 0) {
             // remote host has closed connection
@@ -314,9 +330,9 @@ ssize_t SocketAPM::recv(void *buf, size_t size, uint32_t timeout_ms)
         if (CALL_PREFIX(getsockname)(fd, (struct sockaddr *)&send_addr, &send_len) != 0) {
             return -1;
         }
-        if (in_addr.sin_port == send_addr.sin_port &&
-            in_addr.sin_family == send_addr.sin_family &&
-            in_addr.sin_addr.s_addr == send_addr.sin_addr.s_addr) {
+        if (last_in_addr.sin_port == send_addr.sin_port &&
+            last_in_addr.sin_family == send_addr.sin_family &&
+            last_in_addr.sin_addr.s_addr == send_addr.sin_addr.s_addr) {
             // discard packets from ourselves
             return -1;
         }
@@ -329,8 +345,9 @@ ssize_t SocketAPM::recv(void *buf, size_t size, uint32_t timeout_ms)
  */
 void SocketAPM::last_recv_address(const char *&ip_addr, uint16_t &port) const
 {
-    ip_addr = inet_ntoa(in_addr.sin_addr);
-    port = ntohs(in_addr.sin_port);
+    static char buf[16];
+    auto *str = last_recv_address(buf, sizeof(buf), port);
+    ip_addr = str;
 }
 
 /*
@@ -338,11 +355,11 @@ void SocketAPM::last_recv_address(const char *&ip_addr, uint16_t &port) const
  */
 const char *SocketAPM::last_recv_address(char *ip_addr_buf, uint8_t buflen, uint16_t &port) const
 {
-    const char *ret = inet_ntop(AF_INET, (void*)&in_addr.sin_addr, ip_addr_buf, buflen);
+    const char *ret = CALL_PREFIX(inet_ntop)(AF_INET, (void*)&last_in_addr.sin_addr, ip_addr_buf, buflen);
     if (ret == nullptr) {
         return nullptr;
     }
-    port = ntohs(in_addr.sin_port);
+    port = ntohs(last_in_addr.sin_port);
     return ret;
 }
 
@@ -427,8 +444,8 @@ SocketAPM *SocketAPM::accept(uint32_t timeout_ms)
         return nullptr;
     }
 
-    socklen_t len = sizeof(in_addr);
-    int newfd = CALL_PREFIX(accept)(fd, (sockaddr *)&in_addr, &len);
+    socklen_t len = sizeof(last_in_addr);
+    int newfd = CALL_PREFIX(accept)(fd, (sockaddr *)&last_in_addr, &len);
     if (newfd == -1) {
         return nullptr;
     }
diff --git a/libraries/AP_HAL/utility/Socket.h b/libraries/AP_HAL/utility/Socket.h
index a7bbf45e5b..480281b5d7 100644
--- a/libraries/AP_HAL/utility/Socket.h
+++ b/libraries/AP_HAL/utility/Socket.h
@@ -19,22 +19,12 @@
 
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Networking/AP_Networking_Config.h>
+
 #if AP_NETWORKING_SOCKETS_ENABLED
 
 #if HAL_OS_SOCKETS
 
-#include <fcntl.h>
-#include <unistd.h>
-#include <sys/ioctl.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <sys/select.h>
-#elif AP_NETWORKING_BACKEND_CHIBIOS
-#include <AP_Networking/AP_Networking_ChibiOS.h>
-#include <lwip/sockets.h>
-#endif
+struct sockaddr_in;
 
 class SocketAPM {
 public:
@@ -91,7 +81,13 @@ public:
 
 private:
     bool datagram;
-    struct sockaddr_in in_addr {};
+    struct {
+        uint16_t sin_family;
+        uint16_t sin_port;
+        struct {
+            uint32_t s_addr;
+        } sin_addr;
+    } last_in_addr;
     bool is_multicast_address(struct sockaddr_in &addr) const;
 
     int fd = -1;
@@ -104,4 +100,5 @@ private:
     void make_sockaddr(const char *address, uint16_t port, struct sockaddr_in &sockaddr);
 };
 
+#endif // HAL_OS_SOCKETS
 #endif // AP_NETWORKING_SOCKETS_ENABLED