diff --git a/Makefile b/Makefile
index 8e4f86a..efa9fc4 100644
--- a/Makefile
+++ b/Makefile
@@ -169,7 +169,7 @@ LDLIBS+=-lsocket -lnsl
 endif
 
 ifeq ($(CONFIG_TARGET),mingw)
-CFLAGS+=-I. -I./win32 -DWIN32
+CFLAGS+=-I. -I./win32
 LDLIBS+=$(abspath win32/n2n_win32.a)
 LDLIBS+=-lnetapi32 -lws2_32 -liphlpapi
 N2N_DEPS+=win32/n2n_win32.a
diff --git a/include/n2n.h b/include/n2n.h
index f41f2a4..f86805f 100644
--- a/include/n2n.h
+++ b/include/n2n.h
@@ -42,12 +42,12 @@
 #include "config.h" /* Visual C++ */
 
 /* Moved here to define _CRT_SECURE_NO_WARNINGS before all the including takes place */
-#ifdef WIN32
+#ifdef _WIN32
 #define N2N_CAN_NAME_IFACE 1
 #undef N2N_HAVE_DAEMON
 #undef N2N_HAVE_TCP           /* as explained on https://github.com/ntop/n2n/pull/627#issuecomment-782093706 */
 #undef N2N_HAVE_SETUID
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 
 #include <stdbool.h>
@@ -55,7 +55,7 @@
 #include "n2n_define.h"
 #include "n2n_typedefs.h"
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>           /* for tcp */
 #include <lmaccess.h>           /* for privilege check in tools/n2n-route */
 #include <lmapibuf.h>           /* for privilege check in tools/n2n-route */
@@ -63,9 +63,9 @@
 #include <windows.h>            /* for privilege check in tools/n2n-route */
 #include "wintap.h"
 #define SHUT_RDWR   SD_BOTH     /* for tcp */
-#endif /* #ifdef WIN32 */
+#endif /* #ifdef _WIN32 */
 
-#ifndef WIN32
+#ifndef _WIN32
 #include <netinet/in.h>    // for in_addr (ptr only), in_addr_t
 #include <pwd.h>
 #include <stdint.h>        // for uint8_t, uint64_t, uint32_t, uint16_t
@@ -89,7 +89,7 @@
 #include <openssl/opensslv.h>
 #include <openssl/crypto.h>
 #endif
-#endif /* #ifndef WIN32 */
+#endif /* #ifndef _WIN32 */
 
 
 
@@ -129,7 +129,7 @@ void _traceEvent (int eventTraceLevel, char* file, int line, char * format, ...)
 /* Tuntap API */
 int tuntap_open (struct tuntap_dev *device, char *dev, const char *address_mode, char *device_ip,
                  char *device_mask, const char * device_mac, int mtu
-#ifdef WIN32
+#ifdef _WIN32
 				, int metric
 #endif
                  );
diff --git a/include/n2n_define.h b/include/n2n_define.h
index 27113b9..12c5dc9 100644
--- a/include/n2n_define.h
+++ b/include/n2n_define.h
@@ -190,7 +190,7 @@ enum skip_add {SN_ADD = 0, SN_ADD_SKIP = 1, SN_ADD_ADDED = 2};
 #define N2N_MULTICAST_PORT         1968
 #define N2N_MULTICAST_GROUP        "224.0.0.68"
 
-#ifdef WIN32
+#ifdef _WIN32
 #define N2N_IFNAMSIZ               64
 #else
 #define N2N_IFNAMSIZ               16 /* 15 chars * NULL */
diff --git a/include/n2n_typedefs.h b/include/n2n_typedefs.h
index 4951aa4..0b34f32 100644
--- a/include/n2n_typedefs.h
+++ b/include/n2n_typedefs.h
@@ -21,7 +21,7 @@
 
 #include <stdbool.h>
 #include <stdint.h>     // for uint8_t and friends
-#ifndef WIN32
+#ifndef _WIN32
 #include <arpa/inet.h>  // for in_addr_t
 #include <sys/socket.h> // for sockaddr
 #endif
@@ -84,7 +84,7 @@ typedef unsigned long in_addr_t;
 #endif
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
 #ifndef __LITTLE_ENDIAN__
 #define __LITTLE_ENDIAN__ 1
 #endif
@@ -231,7 +231,7 @@ typedef char dec_ip_bit_str_t[N2N_NETMASK_STR_SIZE + 4];
 typedef char devstr_t[N2N_IFNAMSIZ];
 
 
-#ifndef WIN32
+#ifndef _WIN32
 typedef struct tuntap_dev {
     int                  fd;
     int                  if_idx;
@@ -243,9 +243,9 @@ typedef struct tuntap_dev {
 } tuntap_dev;
 
 #define SOCKET int
-#else /* #ifndef WIN32 */
+#else /* #ifndef _WIN32 */
 typedef u_short sa_family_t;
-#endif /* #ifndef WIN32 */
+#endif /* #ifndef _WIN32 */
 
 
 typedef struct speck_context_t he_context_t;
@@ -574,7 +574,7 @@ typedef struct n2n_tuntap_priv_config {
     int             mtu;
     int             metric;
     uint8_t         daemon;
-#ifndef WIN32
+#ifndef _WIN32
     uid_t           userid;
     gid_t           groupid;
 #endif
@@ -849,7 +849,7 @@ typedef struct n2n_sn {
     int                                    mgmt_sock;       /* management socket. */
     n2n_ip_subnet_t                        min_auto_ip_net; /* Address range of auto_ip service. */
     n2n_ip_subnet_t                        max_auto_ip_net; /* Address range of auto_ip service. */
-#ifndef WIN32
+#ifndef _WIN32
     uid_t                                  userid;
     gid_t                                  groupid;
 #endif
diff --git a/include/n2n_wire.h b/include/n2n_wire.h
index 3e23132..0151bc9 100644
--- a/include/n2n_wire.h
+++ b/include/n2n_wire.h
@@ -25,12 +25,12 @@
 #include <stdint.h>
 #endif
 
-#if defined(WIN32)
+#ifdef _WIN32
 #include "n2n_win32.h"
-#else /* #if defined(WIN32) */
+#else /* #ifdef _WIN32 */
 #include <netinet/in.h>
 #include <sys/socket.h> /* AF_INET and AF_INET6 */
-#endif /* #if defined(WIN32) */
+#endif /* #ifdef _WIN32 */
 
 #include "sn_selection.h"
 
diff --git a/include/random_numbers.h b/include/random_numbers.h
index 2c7eba4..bd7c6ce 100644
--- a/include/random_numbers.h
+++ b/include/random_numbers.h
@@ -38,7 +38,7 @@
 #include <immintrin.h>  /* _rdrand64_step, rdseed4_step */
 #endif
 
-#if defined (WIN32)
+#ifdef _WIN32
 #include <wincrypt.h>   // HCTYPTPROV, Crypt*-functions
 #endif
 
diff --git a/src/edge.c b/src/edge.c
index 5e76ab5..ae9115b 100644
--- a/src/edge.c
+++ b/src/edge.c
@@ -42,7 +42,7 @@
 #include "speck.h"                   // for speck_init, speck_context_t
 #include "uthash.h"                  // for UT_hash_handle, HASH_ADD, HASH_C...
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
@@ -230,12 +230,12 @@ static void help (int level) {
                "[-J <password>] "
                "[-P <public key>] "
                "[-R <rule string>] "
-#ifdef WIN32
+#ifdef _WIN32
             "\n                      "
                "[-x <metric>] "
 #endif
           "\n\n local options        "
-#ifndef WIN32
+#ifndef _WIN32
                "[-f] "
 #endif
                "[-t <management port>] "
@@ -243,7 +243,7 @@ static void help (int level) {
             "\n                      "
                "[-v] "
                "[-V] "
-#ifndef WIN32
+#ifndef _WIN32
             "\n                      "
                "[-u <numerical user id>] "
                "[-g <numerical group id>] "
@@ -266,7 +266,7 @@ static void help (int level) {
           "\n                      [-E]  accept multicast MAC addresses"
           "\n            [--select-rtt]  select supernode by round trip time"
           "\n            [--select-mac]  select supernode by MAC address"
-#ifndef WIN32
+#ifndef _WIN32
           "\n                      [-f]  do not fork but run in foreground"
 #endif
           "\n                      [-v]  make more verbose, repeat as required"
@@ -351,14 +351,14 @@ static void help (int level) {
         printf("                   | rule format:    'src_ip/n:[s_port,e_port],...\n"
                "                   |    |on same|  ...dst_ip/n:[s_port,e_port],...\n"
                "                   |    | line  |  ...TCP+/-,UDP+/-,ICMP+/-'\n");
-#ifdef WIN32
+#ifdef _WIN32
         printf(" -x <metric>       | set TAP interface metric, defaults to 0 (auto),\n"
                "                   | e.g. set to 1 for better multiplayer game detection\n");
 #endif
         printf ("\n");
         printf (" LOCAL OPTIONS\n");
         printf (" -------------\n\n");
-#ifndef WIN32
+#ifndef _WIN32
         printf(" -f                | do not fork and run as a daemon, rather run in foreground\n");
 #endif
         printf(" -t <port>         | management UDP port, for multiple edges on a machine,\n"
@@ -367,7 +367,7 @@ static void help (int level) {
                " ...password <pw>  | \n", N2N_MGMT_PASSWORD);
         printf(" -v                | make more verbose, repeat as required\n");
         printf(" -V                | make less verbose, repeat as required\n");
-#ifndef WIN32
+#ifndef _WIN32
         printf(" -u <UID>          | numeric user ID to use when privileges are dropped\n");
         printf(" -g <GID>          | numeric group ID to use when privileges are dropped\n");
 #endif
@@ -378,7 +378,7 @@ static void help (int level) {
         printf(" N2N_COMMUNITY     | community name (ASCII), overwritten by '-c ...'\n");
         printf(" N2N_PASSWORD      | password (ASCII) for user-password authentication,\n"
                "                   | overwritten by '-J ...'\n");
-#ifdef WIN32
+#ifdef _WIN32
         printf ("\n");
         printf (" AVAILABLE TAP ADAPTERS\n");
         printf (" ----------------------\n\n");
@@ -490,7 +490,7 @@ static int setOption (int optkey, char *optargument, n2n_tuntap_priv_config_t *e
             break;
         }
 
-#ifndef WIN32
+#ifndef _WIN32
         case 'u': /* unprivileged uid */ {
             ec->userid = atoi(optargument);
             break;
@@ -502,12 +502,12 @@ static int setOption (int optkey, char *optargument, n2n_tuntap_priv_config_t *e
         }
 #endif
 
-#ifndef WIN32
+#ifndef _WIN32
         case 'f' : /* do not fork as daemon */ {
             ec->daemon = 0;
             break;
         }
-#endif /* #ifndef WIN32 */
+#endif /* #ifndef _WIN32 */
 
         case 'm' : /* TUNTAP MAC address */ {
             strncpy(ec->device_mac, optargument, N2N_MACNAMSIZ);
@@ -785,7 +785,7 @@ static int setOption (int optkey, char *optargument, n2n_tuntap_priv_config_t *e
             }
             break;
         }
-#ifdef WIN32
+#ifdef _WIN32
         case 'x': {
             conf->metric = atoi(optargument);
             ec->metric = atoi(optargument);
@@ -831,7 +831,7 @@ static int loadFromCLI (int argc, char *argv[], n2n_edge_conf_t *conf, n2n_tunta
 #ifdef __linux__
                             "T:"
 #endif
-#ifdef WIN32
+#ifdef _WIN32
                             "x:"
 #endif
                             ,
@@ -912,7 +912,7 @@ static int loadFromFile (const char *path, n2n_edge_conf_t *conf, n2n_tuntap_pri
 
 /* ************************************** */
 
-#ifndef WIN32
+#ifndef _WIN32
 static void daemonize () {
     int childpid;
 
@@ -961,8 +961,8 @@ static void daemonize () {
 
 static bool keep_on_running = true;
 
-#if defined(__linux__) || defined(WIN32)
-#ifdef WIN32
+#if defined(__linux__) || defined(_WIN32)
+#ifdef _WIN32
 BOOL WINAPI term_handler(DWORD sig)
 #else
     static void term_handler(int sig)
@@ -979,7 +979,7 @@ BOOL WINAPI term_handler(DWORD sig)
     }
 
     keep_on_running = false;
-#ifdef WIN32
+#ifdef _WIN32
     switch (sig) {
         case CTRL_CLOSE_EVENT:
         case CTRL_LOGOFF_EVENT:
@@ -990,7 +990,7 @@ BOOL WINAPI term_handler(DWORD sig)
     return(TRUE);
 #endif
 }
-#endif /* defined(__linux__) || defined(WIN32) */
+#endif /* defined(__linux__) || defined(_WIN32) */
 
 /* *************************************************** */
 
@@ -1015,13 +1015,13 @@ int main (int argc, char* argv[]) {
     uint8_t  pktbuf[N2N_SN_PKTBUF_SIZE + sizeof(uint16_t)]; /* buffer + prepended buffer length in case of tcp */
 
 
-#ifndef WIN32
+#ifndef _WIN32
     struct passwd *pw = NULL;
 #endif
 #ifdef HAVE_LIBCAP
     cap_t caps;
 #endif
-#ifdef WIN32
+#ifdef _WIN32
     initWin32();
 #endif
 
@@ -1031,7 +1031,7 @@ int main (int argc, char* argv[]) {
     ec.mtu = DEFAULT_MTU;
     ec.daemon = 1;        /* By default run in daemon mode. */
 
-#ifndef WIN32
+#ifndef _WIN32
     if(((pw = getpwnam("n2n")) != NULL) ||
        ((pw = getpwnam("nobody")) != NULL)) {
         ec.userid = pw->pw_uid;
@@ -1039,7 +1039,7 @@ int main (int argc, char* argv[]) {
     }
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
     ec.tuntap_dev_name[0] = '\0';
     ec.metric = 0;
 #else
@@ -1055,7 +1055,7 @@ int main (int argc, char* argv[]) {
         rc = loadFromCLI(argc, argv, &conf, &ec);
     else
 
-#ifdef WIN32
+#ifdef _WIN32
         // load from current directory
         rc = loadFromFile("edge.conf", &conf, &ec);
 #else
@@ -1119,7 +1119,7 @@ int main (int argc, char* argv[]) {
     /* Random seed */
     n2n_srand (n2n_seed());
 
-#ifndef WIN32
+#ifndef _WIN32
     /* If running suid root then we need to setuid before using the force. */
     if(setuid(0) != 0)
         traceEvent(TRACE_ERROR, "unable to become root [%u/%s]", errno, strerror(errno));
@@ -1247,7 +1247,7 @@ int main (int argc, char* argv[]) {
             if(tuntap_open(&tuntap, eee->tuntap_priv_conf.tuntap_dev_name, eee->tuntap_priv_conf.ip_mode,
                            eee->tuntap_priv_conf.ip_addr, eee->tuntap_priv_conf.netmask,
                            eee->tuntap_priv_conf.device_mac, eee->tuntap_priv_conf.mtu
-#ifdef WIN32
+#ifdef _WIN32
                            , eee->tuntap_priv_conf.metric
 #endif
                                                            ) < 0)
@@ -1298,7 +1298,7 @@ int main (int argc, char* argv[]) {
     eee->sn_wait = 1;
     eee->last_register_req = 0;
 
-#ifndef WIN32
+#ifndef _WIN32
     if(eee->tuntap_priv_conf.daemon) {
         setUseSyslog(1); /* traceEvent output now goes to syslog. */
         daemonize();
@@ -1340,7 +1340,7 @@ int main (int argc, char* argv[]) {
     signal(SIGTERM, term_handler);
     signal(SIGINT,  term_handler);
 #endif
-#ifdef WIN32
+#ifdef _WIN32
     SetConsoleCtrlHandler(term_handler, TRUE);
 #endif
 
@@ -1365,7 +1365,7 @@ int main (int argc, char* argv[]) {
     tuntap_close(&eee->device);
     edge_term(eee);
 
-#ifdef WIN32
+#ifdef _WIN32
     destroyWin32();
 #endif
 
diff --git a/src/edge_management.c b/src/edge_management.c
index ebf2cfa..4884525 100644
--- a/src/edge_management.c
+++ b/src/edge_management.c
@@ -35,7 +35,7 @@
 #include "strbuf.h"        // for strbuf_t, STRBUF_INIT
 #include "uthash.h"        // for UT_hash_handle, HASH_ITER
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
diff --git a/src/edge_utils.c b/src/edge_utils.c
index f256272..c10711e 100644
--- a/src/edge_utils.c
+++ b/src/edge_utils.c
@@ -40,7 +40,7 @@
 #include "speck.h"                   // for speck_128_decrypt, speck_128_enc...
 #include "uthash.h"                  // for UT_hash_handle, HASH_COUNT, HASH...
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include "edge_utils_win32.h"
@@ -307,7 +307,7 @@ int supernode_connect (n2n_edge_t *eee) {
         // set tcp socket to O_NONBLOCK so connect does not hang
         // requires checking the socket for readiness before sending and receving
         if(eee->conf.connect_tcp) {
-#ifdef WIN32
+#ifdef _WIN32
             u_long value = 1;
             ioctlsocket(eee->sock, FIONBIO, &value);
 #else
@@ -705,7 +705,7 @@ static void register_with_new_peer (n2n_edge_t *eee,
              */
             if(eee->conf.register_ttl == 1) {
                 /* We are DMZ host or port is directly accessible. Just let peer to send back the ack */
-#ifndef WIN32
+#ifndef _WIN32
             } else if(eee->conf.register_ttl > 1) {
                 /* Setting register_ttl usually implies that the edge knows the internal net topology
                  * clearly, we can apply aggressive port prediction to support incoming Symmetric NAT
@@ -1086,7 +1086,7 @@ static ssize_t sendto_fd (n2n_edge_t *eee, const void *buf,
     traceEvent(level, "sendto(%s) failed (%d) %s",
             sock_to_cstr(sockbuf, n2ndest),
             errno, errstr);
-#ifdef WIN32
+#ifdef _WIN32
     traceEvent(level, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
 
@@ -1182,7 +1182,7 @@ static void check_join_multicast_group (n2n_edge_t *eee) {
         if(!eee->multicast_joined) {
             struct ip_mreq mreq;
             mreq.imr_multiaddr.s_addr = inet_addr(N2N_MULTICAST_GROUP);
-#ifdef WIN32
+#ifdef _WIN32
             dec_ip_str_t ip_addr;
             get_best_interface_ip(eee, &ip_addr);
             mreq.imr_interface.s_addr = inet_addr(ip_addr);
@@ -1194,7 +1194,7 @@ static void check_join_multicast_group (n2n_edge_t *eee) {
                 traceEvent(TRACE_WARNING, "failed to bind to local multicast group %s:%u [errno %u]",
                            N2N_MULTICAST_GROUP, N2N_MULTICAST_PORT, errno);
 
-#ifdef WIN32
+#ifdef _WIN32
                 traceEvent(TRACE_WARNING, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
             } else {
@@ -1851,7 +1851,7 @@ static int handle_PACKET (n2n_edge_t * eee,
 
 
 #if 0
-#ifndef WIN32
+#ifndef _WIN32
 
 static char *get_ip_from_arp (dec_ip_str_t buf, const n2n_mac_t req_mac) {
 
@@ -2183,7 +2183,7 @@ void edge_read_from_tap (n2n_edge_t * eee) {
         tuntap_close(&(eee->device));
         tuntap_open(&(eee->device), eee->tuntap_priv_conf.tuntap_dev_name, eee->tuntap_priv_conf.ip_mode, eee->tuntap_priv_conf.ip_addr,
                     eee->tuntap_priv_conf.netmask, eee->tuntap_priv_conf.device_mac, eee->tuntap_priv_conf.mtu
-#ifdef WIN32
+#ifdef _WIN32
 				   ,eee->tuntap_priv_conf.metric
 #endif
                     );
@@ -2795,14 +2795,14 @@ int fetch_and_eventually_process_data (n2n_edge_t *eee, SOCKET sock,
                          sender_sock, &ss_size);
 
         if((bread < 0)
-#ifdef WIN32
+#ifdef _WIN32
            && (WSAGetLastError() != WSAECONNRESET)
 #endif
           ) {
             /* For UDP bread of zero just means no data (unlike TCP). */
             /* The fd is no good now. Maybe we lost our interface. */
             traceEvent(TRACE_ERROR, "recvfrom() failed %d errno %d (%s)", bread, errno, strerror(errno));
-#ifdef WIN32
+#ifdef _WIN32
             traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
             return -1;
@@ -2821,7 +2821,7 @@ int fetch_and_eventually_process_data (n2n_edge_t *eee, SOCKET sock,
                         sender_sock, &ss_size);
         if((bread <= 0) && (errno)) {
             traceEvent(TRACE_ERROR, "recvfrom() failed %d errno %d (%s)", bread, errno, strerror(errno));
-#ifdef WIN32
+#ifdef _WIN32
             traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
             supernode_disconnect(eee);
@@ -2889,7 +2889,7 @@ int run_edge_loop (n2n_edge_t *eee) {
     uint16_t position = 0;
     uint8_t  pktbuf[N2N_PKT_BUF_SIZE + sizeof(uint16_t)]; /* buffer + prepended buffer length in case of tcp */
 
-#ifdef WIN32
+#ifdef _WIN32
     struct tunread_arg arg;
     arg.eee = eee;
     HANDLE tun_read_thread = startTunReadThread(&arg);
@@ -2929,7 +2929,7 @@ int run_edge_loop (n2n_edge_t *eee) {
         }
 #endif
 
-#ifndef WIN32
+#ifndef _WIN32
         FD_SET(eee->device.fd, &socket_mask);
         max_sock = max(max_sock, eee->device.fd);
 #endif
@@ -2989,7 +2989,7 @@ int run_edge_loop (n2n_edge_t *eee) {
                     break;
             }
 
-#ifndef WIN32
+#ifndef _WIN32
             if(FD_ISSET(eee->device.fd, &socket_mask)) {
                 // read an ethernet frame from the TAP socket; write on the IP socket
                 edge_read_from_tap(eee);
@@ -3055,7 +3055,7 @@ int run_edge_loop (n2n_edge_t *eee) {
 
     send_unregister_super(eee);
 
-#ifdef WIN32
+#ifdef _WIN32
     WaitForSingleObject(tun_read_thread, INFINITE);
 #endif
 
@@ -3296,7 +3296,7 @@ int quick_edge_init (char *device_name, char *community_name,
     if(tuntap_open(&tuntap, device_name, "static",
                    local_ip_address, "255.255.255.0",
                    device_mac, DEFAULT_MTU
-#ifdef WIN32
+#ifdef _WIN32
 				 , 0
 #endif
                    ) < 0)
diff --git a/src/edge_utils_win32.c b/src/edge_utils_win32.c
index b65c44c..5f5ea82 100644
--- a/src/edge_utils_win32.c
+++ b/src/edge_utils_win32.c
@@ -16,7 +16,7 @@
  *
  */
 
-#ifdef WIN32
+#ifdef _WIN32
 
 #include <winsock2.h>
 
diff --git a/src/example_edge_embed.c b/src/example_edge_embed.c
index 2b32269..c9d2919 100644
--- a/src/example_edge_embed.c
+++ b/src/example_edge_embed.c
@@ -59,7 +59,7 @@ int main() {
                    "255.255.255.0",     // Netmask to use
                    "DE:AD:BE:EF:01:10", // Set mac address
                    DEFAULT_MTU         // MTU to use
-#ifdef WIN32
+#ifdef _WIN32
 				 , 0
 #endif
                    ) < 0)
diff --git a/src/example_sn_embed.c b/src/example_sn_embed.c
index cdd16ed..7050e40 100644
--- a/src/example_sn_embed.c
+++ b/src/example_sn_embed.c
@@ -21,7 +21,7 @@
 #include <stdlib.h>      // for exit
 #include "n2n.h"         // for n2n_sn_t, open_socket, run_sn_loop, sn_init
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #else
 #include <netinet/in.h>  // for INADDR_ANY, INADDR_LOOPBACK
diff --git a/src/management.c b/src/management.c
index 6f914b5..0aa73b3 100644
--- a/src/management.c
+++ b/src/management.c
@@ -12,7 +12,7 @@
 #include "management.h"
 #include "n2n.h"         // for TRACE_DEBUG, traceEvent
 
-#ifndef WIN32
+#ifndef _WIN32
 #include <netdb.h>       // for getnameinfo, NI_NUMERICHOST, NI_NUMERICSERV
 #include <sys/socket.h>  // for sendto, sockaddr
 #endif
diff --git a/src/management.h b/src/management.h
index 53592bd..3377a98 100644
--- a/src/management.h
+++ b/src/management.h
@@ -16,7 +16,7 @@
 #include "n2n_define.h"    // for n2n_event_topic
 #include "strbuf.h"
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #else
 #include <sys/socket.h>    // for sockaddr, sockaddr_storage, socklen_t
diff --git a/src/n2n.c b/src/n2n.c
index 026a120..bf9df3c 100644
--- a/src/n2n.c
+++ b/src/n2n.c
@@ -34,7 +34,7 @@
 #include <pthread.h>
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2def.h>
 #include <ws2tcpip.h>
@@ -60,7 +60,7 @@ SOCKET open_socket (int local_port, in_addr_t address, int type /* 0 = UDP, TCP
         return(-1);
     }
 
-#ifndef WIN32
+#ifndef _WIN32
     /* fcntl(sock_fd, F_SETFL, O_NONBLOCK); */
 #endif
 
@@ -83,7 +83,7 @@ SOCKET open_socket (int local_port, in_addr_t address, int type /* 0 = UDP, TCP
 
 static int traceLevel = 2 /* NORMAL */;
 static int useSyslog = 0;
-#ifndef WIN32
+#ifndef _WIN32
 static int syslog_opened = 0;
 #endif
 static FILE *traceFile = NULL;
@@ -113,7 +113,7 @@ void closeTraceFile () {
     if((traceFile != NULL) && (traceFile != stdout)) {
         fclose(traceFile);
     }
-#ifndef WIN32
+#ifndef _WIN32
     if(useSyslog && syslog_opened) {
         closelog();
         syslog_opened = 0;
@@ -161,7 +161,7 @@ void _traceEvent (int eventTraceLevel, char* file, int line, char * format, ...)
             buf[strlen(buf) - 1] = '\0';
         }
 
-#ifndef WIN32
+#ifndef _WIN32
         if(useSyslog) {
             if(!syslog_opened) {
                 openlog("n2n", LOG_PID, LOG_DAEMON);
@@ -181,7 +181,7 @@ void _traceEvent (int eventTraceLevel, char* file, int line, char * format, ...)
             snprintf(out_buf, sizeof(out_buf), "%s [%s:%d] %s%s", theDate, &file[i], line, extra_msg, buf);
             fprintf(traceFile, "%s\n", out_buf);
             fflush(traceFile);
-#ifndef WIN32
+#ifndef _WIN32
         }
 #endif
     }
@@ -844,7 +844,7 @@ int memxor (uint8_t *destination, const uint8_t *source, size_t len) {
 
 /* *********************************************** */
 
-#if defined(WIN32)
+#ifdef _WIN32
 int gettimeofday (struct timeval *tp, void *tzp) {
 
     time_t clock;
diff --git a/src/network_traffic_filter.c b/src/network_traffic_filter.c
index 4ba0d0b..ec840a0 100644
--- a/src/network_traffic_filter.c
+++ b/src/network_traffic_filter.c
@@ -25,7 +25,7 @@
 #include "network_traffic_filter.h"  // for create_network_traffic_filter
 #include "uthash.h"                  // for UT_hash_handle, HASH_ITER, HASH_DEL
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
diff --git a/src/random_numbers.c b/src/random_numbers.c
index ed6ca8c..67a1b98 100644
--- a/src/random_numbers.c
+++ b/src/random_numbers.c
@@ -178,7 +178,7 @@ uint64_t n2n_seed (void) {
 #endif
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
     HCRYPTPROV crypto_provider;
     CryptAcquireContext (&crypto_provider, NULL, NULL,
                          PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
diff --git a/src/sn_management.c b/src/sn_management.c
index 2ef8f41..7b3abe4 100644
--- a/src/sn_management.c
+++ b/src/sn_management.c
@@ -35,7 +35,7 @@
 #include "strbuf.h"      // for strbuf_t, STRBUF_INIT
 #include "uthash.h"      // for UT_hash_handle, HASH_ITER, HASH_COUNT
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #else
 #include <sys/socket.h>  // for sendto, socklen_t
diff --git a/src/sn_utils.c b/src/sn_utils.c
index 7f8e806..f6092fe 100644
--- a/src/sn_utils.c
+++ b/src/sn_utils.c
@@ -40,7 +40,7 @@
 #include "speck.h"              // for speck_128_encrypt, speck_context_t
 #include "uthash.h"             // for UT_hash_handle, HASH_ITER, HASH_DEL
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
@@ -512,7 +512,7 @@ static ssize_t sendto_fd (n2n_sn_t *sss,
     if((sent <= 0) && (errno)) {
         char * c = strerror(errno);
         traceEvent(TRACE_ERROR, "sendto failed (%d) %s", errno, c);
-#ifdef WIN32
+#ifdef _WIN32
         traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
         // if the erroneous connection is tcp, i.e. not the regular sock...
@@ -768,7 +768,7 @@ int sn_init_defaults (n2n_sn_t *sss) {
 
     char *tmp_string;
 
-#ifdef WIN32
+#ifdef _WIN32
     initWin32();
 #endif
 
@@ -904,7 +904,7 @@ void sn_term (n2n_sn_t *sss) {
 
     if(sss->community_file)
         free(sss->community_file);
-#ifdef WIN32
+#ifdef _WIN32
     destroyWin32();
 #endif
 }
@@ -2642,14 +2642,14 @@ int run_sn_loop (n2n_sn_t *sss) {
                                  sender_sock, &ss_size);
 
                 if((bread < 0)
-#ifdef WIN32
+#ifdef _WIN32
                    && (WSAGetLastError() != WSAECONNRESET)
 #endif
                   ) {
                     /* For UDP bread of zero just means no data (unlike TCP). */
                     /* The fd is no good now. Maybe we lost our interface. */
                     traceEvent(TRACE_ERROR, "recvfrom() failed %d errno %d (%s)", bread, errno, strerror(errno));
-#ifdef WIN32
+#ifdef _WIN32
                     traceEvent(TRACE_ERROR, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
                     *sss->keep_running = false;
@@ -2688,7 +2688,7 @@ int run_sn_loop (n2n_sn_t *sss) {
                     if(bread <= 0) {
                         traceEvent(TRACE_INFO, "closing tcp connection to [%s]", sock_to_cstr(sockbuf, (n2n_sock_t*)sender_sock));
                         traceEvent(TRACE_DEBUG, "recvfrom() returns %d and sees errno %d (%s)", bread, errno, strerror(errno));
-#ifdef WIN32
+#ifdef _WIN32
                         traceEvent(TRACE_DEBUG, "WSAGetLastError(): %u", WSAGetLastError());
 #endif
                         close_tcp_connection(sss, conn);
diff --git a/src/supernode.c b/src/supernode.c
index 2f60416..8d39a4c 100644
--- a/src/supernode.c
+++ b/src/supernode.c
@@ -35,7 +35,7 @@
 #include "pearson.h"           // for pearson_hash_64
 #include "uthash.h"            // for UT_hash_handle, HASH_ITER, HASH_ADD_STR
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
@@ -107,7 +107,7 @@ static void help (int level) {
             "\n                           "
                "[--management-password <pw>] "
                "[-v] "
-#ifndef WIN32
+#ifndef _WIN32
             "\n                           "
                "[-u <numerical user id>]"
                "[-g <numerical group id>]"
@@ -168,7 +168,7 @@ static void help (int level) {
         printf(" --management_...  | management port password, defaults to '%s'\n"
                " ...password <pw>  | \n", N2N_MGMT_PASSWORD);
         printf(" -v                | make more verbose, repeat as required\n");
-#ifndef WIN32
+#ifndef _WIN32
         printf(" -u <UID>          | numeric user ID to use when privileges are dropped\n");
         printf(" -g <GID>          | numeric group ID to use when privileges are dropped\n");
 #endif
@@ -324,7 +324,7 @@ static int setOption (int optkey, char *_optarg, n2n_sn_t *sss) {
 
             break;
         }
-#ifndef WIN32
+#ifndef _WIN32
         case 'u': /* unprivileged uid */
             sss->userid = atoi(_optarg);
             break;
@@ -425,7 +425,7 @@ static int loadFromCLI (int argc, char * const argv[], n2n_sn_t *sss) {
 #if defined(N2N_HAVE_DAEMON)
                            "f"
 #endif
-#ifndef WIN32
+#ifndef _WIN32
                            "u:g:"
 #endif
                             ,
@@ -567,8 +567,8 @@ static void dump_registrations (int signo) {
 
 static bool keep_running = true;
 
-#if defined(__linux__) || defined(WIN32)
-#ifdef WIN32
+#if defined(__linux__) || defined(_WIN32)
+#ifdef _WIN32
 BOOL WINAPI term_handler (DWORD sig)
 #else
     static void term_handler(int sig)
@@ -585,11 +585,11 @@ BOOL WINAPI term_handler (DWORD sig)
     }
 
     keep_running = false;
-#ifdef WIN32
+#ifdef _WIN32
     return(TRUE);
 #endif
 }
-#endif /* defined(__linux__) || defined(WIN32) */
+#endif /* defined(__linux__) || defined(_WIN32) */
 
 /* *************************************************** */
 
@@ -597,7 +597,7 @@ BOOL WINAPI term_handler (DWORD sig)
 int main (int argc, char * const argv[]) {
 
     int rc;
-#ifndef WIN32
+#ifndef _WIN32
     struct passwd *pw = NULL;
 #endif
     struct peer_info *scan, *tmp;
@@ -615,7 +615,7 @@ int main (int argc, char * const argv[]) {
         rc = loadFromCLI(argc, argv, &sss_node);
     } else
 
-#ifdef WIN32
+#ifdef _WIN32
         // load from current directory
         rc = loadFromFile("supernode.conf", &sss_node);
 #else
@@ -689,7 +689,7 @@ int main (int argc, char * const argv[]) {
     HASH_ITER(hh, sss_node.federation->edges, scan, tmp)
         scan->socket_fd = sss_node.sock;
 
-#ifndef WIN32
+#ifndef _WIN32
     /*
      * If no uid/gid is specified on the commandline, use the uid/gid of the
      * first found out of user "n2n" or "nobody"
@@ -734,7 +734,7 @@ int main (int argc, char * const argv[]) {
     signal(SIGINT,  term_handler);
     signal(SIGHUP,  dump_registrations);
 #endif
-#ifdef WIN32
+#ifdef _WIN32
     SetConsoleCtrlHandler(term_handler, TRUE);
 #endif
 
diff --git a/src/wire.c b/src/wire.c
index 485020f..995efe8 100644
--- a/src/wire.c
+++ b/src/wire.c
@@ -33,7 +33,7 @@
 #include "n2n.h"         // for n2n_sock_t, n2n_common_t, n2n_auth_t, n2n_RE...
 #include "n2n_wire.h"    // for decode_PACKET, decode_PEER_INFO, decode_QUER...
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #else
diff --git a/tools/n2n-decode.c b/tools/n2n-decode.c
index cf5844b..c11211c 100644
--- a/tools/n2n-decode.c
+++ b/tools/n2n-decode.c
@@ -58,7 +58,7 @@ static void help() {
 
 /* *************************************************** */
 
-#ifdef WIN32
+#ifdef _WIN32
 BOOL WINAPI term_handler(DWORD sig)
 #else
 static void term_handler(int sig)
@@ -75,7 +75,7 @@ static void term_handler(int sig)
   }
 
   running = 0;
-#ifdef WIN32
+#ifdef _WIN32
   return(TRUE);
 #endif
 }
@@ -349,7 +349,7 @@ int main(int argc, char* argv[]) {
     return(5);
   }
 
-#ifdef WIN32
+#ifdef _WIN32
   SetConsoleCtrlHandler(term_handler, TRUE);
 #else
   signal(SIGTERM, term_handler);
diff --git a/tools/n2n-portfwd.c b/tools/n2n-portfwd.c
index 1b6a7e9..dce283a 100644
--- a/tools/n2n-portfwd.c
+++ b/tools/n2n-portfwd.c
@@ -33,7 +33,7 @@
 #include "n2n_port_mapping.h"  // for n2n_del_port_mapping, n2n_set_port_map...
 #include "random_numbers.h"    // for n2n_rand, n2n_seed, n2n_srand
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock.h>
 #include <ws2tcpip.h>
 #else
@@ -49,7 +49,7 @@
 #define INFO_INTERVAL           5
 
 // REVISIT: may become obsolete
-#ifdef WIN32
+#ifdef _WIN32
 #ifndef STDIN_FILENO
 #define STDIN_FILENO            _fileno(stdin)
 #endif
@@ -75,13 +75,13 @@ void set_term_handler(const void *handler) {
     signal(SIGTERM, handler);
     signal(SIGINT, handler);
 #endif
-#ifdef WIN32
+#ifdef _WIN32
     SetConsoleCtrlHandler(handler, TRUE);
 #endif
 }
 
 
-#ifdef WIN32
+#ifdef _WIN32
 BOOL WINAPI term_handler (DWORD sig) {
 #else
 static void term_handler (int sig) {
@@ -98,7 +98,7 @@ static void term_handler (int sig) {
     }
 
     keep_running = false;
-#ifdef WIN32
+#ifdef _WIN32
     return TRUE;
 #endif
 }
@@ -113,7 +113,7 @@ SOCKET connect_to_management_port (n2n_portfwd_conf_t *ppp) {
     SOCKET ret;
     struct sockaddr_in sock_addr;
 
-#if defined(WIN32)
+#ifdef _WIN32
     // Windows requires a call to WSAStartup() before it can work with sockets
     WORD wVersionRequested;
     WSADATA wsaData;
@@ -184,7 +184,7 @@ int get_port_from_json (uint16_t *port, json_object_t *json, char *key, int tag,
 // PLATFORM-DEPENDANT CODE
 
 
-#if !defined(WIN32)
+#ifndef _WIN32
 // taken from https://web.archive.org/web/20170407122137/http://cc.byexamples.com/2007/04/08/non-blocking-user-input-in-loop-without-ncurses/
 int _kbhit () {
 
diff --git a/tools/n2n-route.c b/tools/n2n-route.c
index aeaa49d..fa63fa2 100644
--- a/tools/n2n-route.c
+++ b/tools/n2n-route.c
@@ -38,7 +38,7 @@
 #include <linux/rtnetlink.h>   // for RTA_DATA, rtmsg, RTA_GATEWAY, RTA_NEXT
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <winsock.h>
 #include <ws2tcpip.h>
 #else
@@ -51,7 +51,7 @@
 #include <sys/socket.h>        // for send, socket, AF_INET, recv, connect
 #endif
 
-#if defined (__linux__) || defined(WIN32)  /*  currently, Linux and Windows only */
+#if defined (__linux__) || defined(_WIN32)  /*  currently, Linux and Windows only */
 
 
 #define WITH_ADDRESS            1
@@ -74,7 +74,7 @@
 #define AUTO_DETECT            1
 
 // REVISIT: may become obsolete
-#ifdef WIN32
+#ifdef _WIN32
 #ifndef STDIN_FILENO
 #define STDIN_FILENO            _fileno(stdin)
 #endif
@@ -117,7 +117,7 @@ int is_privileged (void) {
 
     return euid == 0;
 
-#elif defined(WIN32)
+#elif defined(_WIN32)
 // taken from https://stackoverflow.com/a/10553065
         int result;
         DWORD rc;
@@ -148,13 +148,13 @@ void set_term_handler(const void *handler) {
     signal(SIGPIPE, SIG_IGN);
     signal(SIGTERM, handler);
     signal(SIGINT, handler);
-#elif defined(WIN32)
+#elif defined(_WIN32)
     SetConsoleCtrlHandler(handler, TRUE);
 #endif
 }
 
 
-#if !defined(WIN32)
+#ifndef _WIN32
 static void term_handler (int sig) {
 #else
 BOOL WINAPI term_handler (DWORD sig) {
@@ -171,7 +171,7 @@ BOOL WINAPI term_handler (DWORD sig) {
     }
 
     keep_running = false;
-#if defined(WIN32)
+#ifdef _WIN32
     return TRUE;
 #endif
 }
@@ -317,7 +317,7 @@ find_default_gateway_end:
     closesocket(sock);
     return ret;
 
-#elif defined(WIN32)
+#elif defined(_WIN32)
     // taken from (and modified)
     // https://docs.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-createipforwardentry
 
@@ -376,7 +376,7 @@ find_default_gateway_end:
 // PLATFORM-DEPENDANT CODE
 
 
-#if defined(WIN32)
+#ifdef _WIN32
 DWORD get_interface_index (struct in_addr addr) {
     // taken from (and modified)
     // https://docs.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-createipforwardentry
@@ -496,7 +496,7 @@ void handle_route (n2n_route_t* in_route, int verb) {
 
     closesocket(sock);
 
-#elif defined(WIN32)
+#elif defined(_WIN32)
     // REVISIT: use 'CreateIpForwardEntry()' and 'DeleteIpForwardEntry()' [iphlpapi.h]
     char c_net_addr[32];
     char c_gateway[32];
@@ -573,7 +573,7 @@ SOCKET connect_to_management_port (n2n_route_conf_t *rrr) {
     SOCKET ret;
     struct sockaddr_in sock_addr;
 
-#if defined(WIN32)
+#ifdef _WIN32
     // Windows requires a call to WSAStartup() before it can work with sockets
     WORD wVersionRequested;
     WSADATA wsaData;
@@ -643,7 +643,7 @@ int get_addr_from_json (struct in_addr *addr, json_object_t *json, char *key, in
 // PLATFORM-DEPENDANT CODE
 
 
-#if !defined(WIN32)
+#ifndef _WIN32
 // taken from https://web.archive.org/web/20170407122137/http://cc.byexamples.com/2007/04/08/non-blocking-user-input-in-loop-without-ncurses/
 int _kbhit () {
 
@@ -1088,7 +1088,7 @@ end_route_tool:
 }
 
 
-#else  /* if defined(__linux__) || defined(WIN32) --  currently, Linux and Windows only */
+#else  /* if defined(__linux__) || defined(_WIN32) --  currently, Linux and Windows only */
 
 
 int main (int argc, char* argv[]) {
@@ -1100,4 +1100,4 @@ int main (int argc, char* argv[]) {
 }
 
 
-#endif /* if defined (__linux__) || defined(WIN32)  --  currently, Linux and Windows only */
+#endif /* if defined (__linux__) || defined(_WIN32)  --  currently, Linux and Windows only */
diff --git a/win32/getopt.c b/win32/getopt.c
index f34b53a..3e51545 100644
--- a/win32/getopt.c
+++ b/win32/getopt.c
@@ -58,7 +58,7 @@
 #endif
 
 #include <stdio.h>
-#ifdef WIN32
+#ifdef _WIN32
 #include <string.h>
 #endif
 
@@ -171,7 +171,7 @@ static char *nextchar;
    for unrecognized options.  */
 
 #ifndef DARWIN
-#ifdef WIN32
+#ifdef _WIN32
 int opterr = 0;
 #else
 int opterr = 1;
@@ -231,7 +231,7 @@ static char *posixly_correct;
 # define my_index	strchr
 #else
 
-#ifndef WIN32
+#ifndef _WIN32
 # if HAVE_STRING_H
 #  include <string.h>
 # else