diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5af6833e..7ec2b242 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,6 +32,7 @@ if(DEBUG)
   check_c_compiler_flag("-g3" HAVE_G3)
   if(HAVE_G3)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g3")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g3")
   endif()
 endif()
 
@@ -56,6 +57,7 @@ if(ASAN)
   check_c_compiler_flag("-fsanitize=address" HAVE_ASAN)
   if(HAVE_ASAN)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
   endif()
   set(CMAKE_REQUIRED_LIBRARIES "${SAFE_CMAKE_REQUIRED_LIBRARIES}")
 endif()
diff --git a/auto_tests/TCP_test.c b/auto_tests/TCP_test.c
index 1442dcae..77327299 100644
--- a/auto_tests/TCP_test.c
+++ b/auto_tests/TCP_test.c
@@ -63,13 +63,14 @@ START_TEST(test_basic)
                        TCP_HANDSHAKE_PLAIN_SIZE, handshake + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES);
     ck_assert_msg(ret == TCP_CLIENT_HANDSHAKE_SIZE - (crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES),
                   "Encrypt failed.");
-    ck_assert_msg(send(sock, handshake, TCP_CLIENT_HANDSHAKE_SIZE - 1, 0) == TCP_CLIENT_HANDSHAKE_SIZE - 1, "send Failed.");
+    ck_assert_msg(send(sock, (const char *)handshake, TCP_CLIENT_HANDSHAKE_SIZE - 1, 0) == TCP_CLIENT_HANDSHAKE_SIZE - 1,
+                  "send Failed.");
     c_sleep(50);
     do_TCP_server(tcp_s);
     c_sleep(50);
     do_TCP_server(tcp_s);
     c_sleep(50);
-    ck_assert_msg(send(sock, handshake + (TCP_CLIENT_HANDSHAKE_SIZE - 1), 1, 0) == 1, "send Failed.");
+    ck_assert_msg(send(sock, (const char *)(handshake + (TCP_CLIENT_HANDSHAKE_SIZE - 1)), 1, 0) == 1, "send Failed.");
     c_sleep(50);
     do_TCP_server(tcp_s);
     c_sleep(50);
@@ -77,7 +78,7 @@ START_TEST(test_basic)
     c_sleep(50);
     uint8_t response[TCP_SERVER_HANDSHAKE_SIZE];
     uint8_t response_plain[TCP_HANDSHAKE_PLAIN_SIZE];
-    ck_assert_msg(recv(sock, response, TCP_SERVER_HANDSHAKE_SIZE, 0) == TCP_SERVER_HANDSHAKE_SIZE, "recv Failed.");
+    ck_assert_msg(recv(sock, (char *)response, TCP_SERVER_HANDSHAKE_SIZE, 0) == TCP_SERVER_HANDSHAKE_SIZE, "recv Failed.");
     ret = decrypt_data(self_public_key, f_secret_key, response, response + crypto_box_NONCEBYTES,
                        TCP_SERVER_HANDSHAKE_SIZE - crypto_box_NONCEBYTES, response_plain);
     ck_assert_msg(ret == TCP_HANDSHAKE_PLAIN_SIZE, "Decrypt Failed.");
@@ -97,8 +98,8 @@ START_TEST(test_basic)
     uint32_t i;
 
     for (i = 0; i < sizeof(r_req); ++i) {
-        ck_assert_msg(send(sock, r_req + i, 1, 0) == 1, "send Failed.");
-        //ck_assert_msg(send(sock, r_req, sizeof(r_req), 0) == sizeof(r_req), "send Failed.");
+        ck_assert_msg(send(sock, (const char *)(r_req + i), 1, 0) == 1, "send Failed.");
+        //ck_assert_msg(send(sock, (const char *)r_req, sizeof(r_req), 0) == sizeof(r_req), "send Failed.");
         do_TCP_server(tcp_s);
         c_sleep(50);
     }
@@ -106,7 +107,7 @@ START_TEST(test_basic)
     do_TCP_server(tcp_s);
     c_sleep(50);
     uint8_t packet_resp[4096];
-    int recv_data_len = recv(sock, packet_resp, 2 + 2 + crypto_box_PUBLICKEYBYTES + crypto_box_MACBYTES, 0);
+    int recv_data_len = recv(sock, (char *)packet_resp, 2 + 2 + crypto_box_PUBLICKEYBYTES + crypto_box_MACBYTES, 0);
     ck_assert_msg(recv_data_len == 2 + 2 + crypto_box_PUBLICKEYBYTES + crypto_box_MACBYTES,
                   "recv Failed. %u", recv_data_len);
     memcpy(&size, packet_resp, 2);
@@ -158,15 +159,16 @@ static struct sec_TCP_con *new_TCP_con(TCP_Server *tcp_s)
                        TCP_HANDSHAKE_PLAIN_SIZE, handshake + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES);
     ck_assert_msg(ret == TCP_CLIENT_HANDSHAKE_SIZE - (crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES),
                   "Encrypt failed.");
-    ck_assert_msg(send(sock, handshake, TCP_CLIENT_HANDSHAKE_SIZE - 1, 0) == TCP_CLIENT_HANDSHAKE_SIZE - 1, "send Failed.");
+    ck_assert_msg(send(sock, (const char *)handshake, TCP_CLIENT_HANDSHAKE_SIZE - 1, 0) == TCP_CLIENT_HANDSHAKE_SIZE - 1,
+                  "send Failed.");
     do_TCP_server(tcp_s);
     c_sleep(50);
-    ck_assert_msg(send(sock, handshake + (TCP_CLIENT_HANDSHAKE_SIZE - 1), 1, 0) == 1, "send Failed.");
+    ck_assert_msg(send(sock, (const char *)(handshake + (TCP_CLIENT_HANDSHAKE_SIZE - 1)), 1, 0) == 1, "send Failed.");
     c_sleep(50);
     do_TCP_server(tcp_s);
     uint8_t response[TCP_SERVER_HANDSHAKE_SIZE];
     uint8_t response_plain[TCP_HANDSHAKE_PLAIN_SIZE];
-    ck_assert_msg(recv(sock, response, TCP_SERVER_HANDSHAKE_SIZE, 0) == TCP_SERVER_HANDSHAKE_SIZE, "recv Failed.");
+    ck_assert_msg(recv(sock, (char *)response, TCP_SERVER_HANDSHAKE_SIZE, 0) == TCP_SERVER_HANDSHAKE_SIZE, "recv Failed.");
     ret = decrypt_data(tcp_server_public_key(tcp_s), f_secret_key, response, response + crypto_box_NONCEBYTES,
                        TCP_SERVER_HANDSHAKE_SIZE - crypto_box_NONCEBYTES, response_plain);
     ck_assert_msg(ret == TCP_HANDSHAKE_PLAIN_SIZE, "Decrypt Failed.");
@@ -196,13 +198,13 @@ static int write_packet_TCP_secure_connection(struct sec_TCP_con *con, uint8_t *
 
     increment_nonce(con->sent_nonce);
 
-    ck_assert_msg(send(con->sock, packet, sizeof(packet), 0) == sizeof(packet), "send failed");
+    ck_assert_msg(send(con->sock, (const char *)packet, sizeof(packet), 0) == sizeof(packet), "send failed");
     return 0;
 }
 
 static int read_packet_sec_TCP(struct sec_TCP_con *con, uint8_t *data, uint16_t length)
 {
-    int len = recv(con->sock, data, length, 0);
+    int len = recv(con->sock, (char *)data, length, 0);
     ck_assert_msg(len == length, "wrong len %i\n", len);
     len = decrypt_data_symmetric(con->shared_key, con->recv_nonce, data + 2, length - 2, data);
     ck_assert_msg(len != -1, "Decrypt failed");
diff --git a/auto_tests/conference_test.c b/auto_tests/conference_test.c
index 0f1e2ca4..fba64bcc 100644
--- a/auto_tests/conference_test.c
+++ b/auto_tests/conference_test.c
@@ -6,10 +6,10 @@
 #endif
 
 #include <check.h>
+#include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
-#include <inttypes.h>
 
 #include "../toxcore/tox.h"
 #include "../toxcore/util.h"
diff --git a/auto_tests/tox_many_tcp_test.c b/auto_tests/tox_many_tcp_test.c
index 146d4fd2..59d69c49 100644
--- a/auto_tests/tox_many_tcp_test.c
+++ b/auto_tests/tox_many_tcp_test.c
@@ -8,6 +8,7 @@
 #include <check.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include "../toxcore/tox.h"
 #include "../toxcore/util.h"
diff --git a/auto_tests/tox_many_test.c b/auto_tests/tox_many_test.c
index 656d1769..fa657580 100644
--- a/auto_tests/tox_many_test.c
+++ b/auto_tests/tox_many_test.c
@@ -8,6 +8,7 @@
 #include <check.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include "../toxcore/tox.h"
 #include "../toxcore/util.h"
diff --git a/auto_tests/tox_one_test.c b/auto_tests/tox_one_test.c
index 748d1224..1248de19 100644
--- a/auto_tests/tox_one_test.c
+++ b/auto_tests/tox_one_test.c
@@ -7,6 +7,7 @@
 
 #include <check.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include "../toxcore/tox.h"
 #include "../toxcore/util.h"
diff --git a/auto_tests/tox_test.c b/auto_tests/tox_test.c
index 53f94bc5..2706e564 100644
--- a/auto_tests/tox_test.c
+++ b/auto_tests/tox_test.c
@@ -17,6 +17,7 @@
 #include <check.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include "../toxcore/tox.h"
 #include "../toxcore/util.h"
diff --git a/cmake/ModulePackage.cmake b/cmake/ModulePackage.cmake
index fa3779c3..a556aef0 100644
--- a/cmake/ModulePackage.cmake
+++ b/cmake/ModulePackage.cmake
@@ -4,7 +4,12 @@ option(COMPILE_AS_CXX "Compile all C code as C++ code" OFF)
 
 find_package(PkgConfig REQUIRED)
 
-function(set_source_language)
+if(COMPILE_AS_CXX)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__STDC_FORMAT_MACROS=1")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__STDC_LIMIT_MACROS=1")
+endif()
+
+macro(set_source_language)
   if(COMPILE_AS_CXX)
     foreach(srcfile ${ARGN})
       get_filename_component(srcext ${srcfile} EXT)
@@ -13,10 +18,11 @@ function(set_source_language)
       endif()
     endforeach()
   endif()
-endfunction()
+endmacro()
 
 function(add_c_executable exec)
   set_source_language(${ARGN})
+
   add_executable(${exec} ${ARGN})
 endfunction()
 
@@ -26,6 +32,7 @@ function(pkg_use_module mod)
     link_directories(${${mod}_LIBRARY_DIRS})
     include_directories(${${mod}_INCLUDE_DIRS})
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${${mod}_CFLAGS_OTHER}")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${mod}_CFLAGS_OTHER}")
   endif()
 endfunction()
 
diff --git a/other/travis/env-windows.sh b/other/travis/env-windows.sh
index 8c9b9c65..44f486af 100644
--- a/other/travis/env-windows.sh
+++ b/other/travis/env-windows.sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 CMAKE=$ARCH-w64-mingw32.shared-cmake
-CMAKE_EXTRA_FLAGS="-DBOOTSTRAP_DAEMON=OFF"
+CMAKE_EXTRA_FLAGS="-DBOOTSTRAP_DAEMON=OFF -DCOMPILE_AS_CXX=ON"
 NPROC=`nproc`
 CURDIR=/work
 
diff --git a/testing/dns3_test.c b/testing/dns3_test.c
index 3151dd99..7356bc00 100644
--- a/testing/dns3_test.c
+++ b/testing/dns3_test.c
@@ -98,12 +98,12 @@ int main(int argc, char *argv[])
     uint8_t id = rand();
     uint32_t p_len = create_packet(packet, string, strlen((char *)string), id);
 
-    if (sendto(sock, (char *) packet, p_len, 0, (struct sockaddr *)&target, addrsize) != p_len) {
+    if (sendto(sock, (char *)packet, p_len, 0, (struct sockaddr *)&target, addrsize) != p_len) {
         return -1;
     }
 
     uint8_t buffer[512] = {0};
-    int r_len = recv(sock, buffer, sizeof(buffer), 0);
+    int r_len = recv(sock, (char *)buffer, sizeof(buffer), 0);
 
     if (r_len < (int)p_len) {
         return -1;
diff --git a/toxcore/LAN_discovery.c b/toxcore/LAN_discovery.c
index d2bfb4e1..48e0e7bb 100644
--- a/toxcore/LAN_discovery.c
+++ b/toxcore/LAN_discovery.c
@@ -50,7 +50,7 @@ static void fetch_broadcast_info(uint16_t port)
 {
     broadcast_count = 0;
 
-    IP_ADAPTER_INFO *pAdapterInfo = malloc(sizeof(IP_ADAPTER_INFO));
+    IP_ADAPTER_INFO *pAdapterInfo = (IP_ADAPTER_INFO *)malloc(sizeof(IP_ADAPTER_INFO));
     unsigned long ulOutBufLen = sizeof(IP_ADAPTER_INFO);
 
     if (pAdapterInfo == NULL) {
@@ -59,7 +59,7 @@ static void fetch_broadcast_info(uint16_t port)
 
     if (GetAdaptersInfo(pAdapterInfo, &ulOutBufLen) == ERROR_BUFFER_OVERFLOW) {
         free(pAdapterInfo);
-        pAdapterInfo = malloc(ulOutBufLen);
+        pAdapterInfo = (IP_ADAPTER_INFO *)malloc(ulOutBufLen);
 
         if (pAdapterInfo == NULL) {
             return;
diff --git a/toxcore/TCP_client.c b/toxcore/TCP_client.c
index ba8aeabe..caa1b73d 100644
--- a/toxcore/TCP_client.c
+++ b/toxcore/TCP_client.c
@@ -272,7 +272,7 @@ static int send_pending_data_nonpriority(TCP_Client_Connection *con)
     }
 
     uint16_t left = con->last_packet_length - con->last_packet_sent;
-    int len = send(con->sock, con->last_packet + con->last_packet_sent, left, MSG_NOSIGNAL);
+    int len = send(con->sock, (const char *)(con->last_packet + con->last_packet_sent), left, MSG_NOSIGNAL);
 
     if (len <= 0) {
         return -1;
@@ -302,7 +302,7 @@ static int send_pending_data(TCP_Client_Connection *con)
 
     while (p) {
         uint16_t left = p->size - p->sent;
-        int len = send(con->sock, p->data + p->sent, left, MSG_NOSIGNAL);
+        int len = send(con->sock, (const char *)(p->data + p->sent), left, MSG_NOSIGNAL);
 
         if (len != left) {
             if (len > 0) {
@@ -397,7 +397,7 @@ static int write_packet_TCP_secure_connection(TCP_Client_Connection *con, const
     }
 
     if (priority) {
-        len = sendpriority ? send(con->sock, packet, sizeof(packet), MSG_NOSIGNAL) : 0;
+        len = sendpriority ? send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL) : 0;
 
         if (len <= 0) {
             len = 0;
@@ -412,7 +412,7 @@ static int write_packet_TCP_secure_connection(TCP_Client_Connection *con, const
         return add_priority(con, packet, sizeof(packet), len);
     }
 
-    len = send(con->sock, packet, sizeof(packet), MSG_NOSIGNAL);
+    len = send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL);
 
     if (len <= 0) {
         return 0;
diff --git a/toxcore/TCP_server.c b/toxcore/TCP_server.c
index 5a5a55be..4b355a62 100644
--- a/toxcore/TCP_server.c
+++ b/toxcore/TCP_server.c
@@ -251,7 +251,7 @@ uint16_t read_TCP_length(sock_t sock)
 
     if (count >= sizeof(uint16_t)) {
         uint16_t length;
-        int len = recv(sock, (uint8_t *)&length, sizeof(uint16_t), MSG_NOSIGNAL);
+        int len = recv(sock, (char *)&length, sizeof(uint16_t), MSG_NOSIGNAL);
 
         if (len != sizeof(uint16_t)) {
             fprintf(stderr, "FAIL recv packet\n");
@@ -280,7 +280,7 @@ int read_TCP_packet(sock_t sock, uint8_t *data, uint16_t length)
     unsigned int count = TCP_socket_data_recv_buffer(sock);
 
     if (count >= length) {
-        int len = recv(sock, data, length, MSG_NOSIGNAL);
+        int len = recv(sock, (char *)data, length, MSG_NOSIGNAL);
 
         if (len != length) {
             fprintf(stderr, "FAIL recv packet\n");
@@ -348,7 +348,7 @@ static int send_pending_data_nonpriority(TCP_Secure_Connection *con)
     }
 
     uint16_t left = con->last_packet_length - con->last_packet_sent;
-    int len = send(con->sock, con->last_packet + con->last_packet_sent, left, MSG_NOSIGNAL);
+    int len = send(con->sock, (const char *)(con->last_packet + con->last_packet_sent), left, MSG_NOSIGNAL);
 
     if (len <= 0) {
         return -1;
@@ -378,7 +378,7 @@ static int send_pending_data(TCP_Secure_Connection *con)
 
     while (p) {
         uint16_t left = p->size - p->sent;
-        int len = send(con->sock, p->data + p->sent, left, MSG_NOSIGNAL);
+        int len = send(con->sock, (const char *)(p->data + p->sent), left, MSG_NOSIGNAL);
 
         if (len != left) {
             if (len > 0) {
@@ -462,7 +462,7 @@ static int write_packet_TCP_secure_connection(TCP_Secure_Connection *con, const
     }
 
     if (priority) {
-        len = sendpriority ? send(con->sock, packet, sizeof(packet), MSG_NOSIGNAL) : 0;
+        len = sendpriority ? send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL) : 0;
 
         if (len <= 0) {
             len = 0;
@@ -477,7 +477,7 @@ static int write_packet_TCP_secure_connection(TCP_Secure_Connection *con, const
         return add_priority(con, packet, sizeof(packet), len);
     }
 
-    len = send(con->sock, packet, sizeof(packet), MSG_NOSIGNAL);
+    len = send(con->sock, (const char *)packet, sizeof(packet), MSG_NOSIGNAL);
 
     if (len <= 0) {
         return 0;
@@ -574,7 +574,7 @@ static int handle_TCP_handshake(TCP_Secure_Connection *con, const uint8_t *data,
         return -1;
     }
 
-    if (TCP_SERVER_HANDSHAKE_SIZE != send(con->sock, response, TCP_SERVER_HANDSHAKE_SIZE, MSG_NOSIGNAL)) {
+    if (TCP_SERVER_HANDSHAKE_SIZE != send(con->sock, (const char *)response, TCP_SERVER_HANDSHAKE_SIZE, MSG_NOSIGNAL)) {
         return -1;
     }
 
diff --git a/toxcore/network.c b/toxcore/network.c
index 386f8c16..31e8fd8b 100644
--- a/toxcore/network.c
+++ b/toxcore/network.c
@@ -170,7 +170,7 @@ int set_socket_nosigpipe(sock_t sock)
 {
 #if defined(__MACH__)
     int set = 1;
-    return (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int)) == 0);
+    return (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (const char *)&set, sizeof(int)) == 0);
 #else
     return 1;
 #endif
@@ -184,7 +184,7 @@ int set_socket_nosigpipe(sock_t sock)
 int set_socket_reuseaddr(sock_t sock)
 {
     int set = 1;
-    return (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&set, sizeof(set)) == 0);
+    return (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const char *)&set, sizeof(set)) == 0);
 }
 
 /* Set socket to dual (IPv4 + IPv6 socket)
@@ -196,14 +196,14 @@ int set_socket_dualstack(sock_t sock)
 {
     int ipv6only = 0;
     socklen_t optsize = sizeof(ipv6only);
-    int res = getsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&ipv6only, &optsize);
+    int res = getsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&ipv6only, &optsize);
 
     if ((res == 0) && (ipv6only == 0)) {
         return 1;
     }
 
     ipv6only = 0;
-    return (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&ipv6only, sizeof(ipv6only)) == 0);
+    return (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (const char *)&ipv6only, sizeof(ipv6only)) == 0);
 }
 
 
@@ -588,12 +588,12 @@ Networking_Core *new_networking_ex(Logger *log, IP ip, uint16_t port_from, uint1
     /* Functions to increase the size of the send and receive UDP buffers.
      */
     int n = 1024 * 1024 * 2;
-    setsockopt(temp->sock, SOL_SOCKET, SO_RCVBUF, (char *)&n, sizeof(n));
-    setsockopt(temp->sock, SOL_SOCKET, SO_SNDBUF, (char *)&n, sizeof(n));
+    setsockopt(temp->sock, SOL_SOCKET, SO_RCVBUF, (const char *)&n, sizeof(n));
+    setsockopt(temp->sock, SOL_SOCKET, SO_SNDBUF, (const char *)&n, sizeof(n));
 
     /* Enable broadcast on socket */
     int broadcast = 1;
-    setsockopt(temp->sock, SOL_SOCKET, SO_BROADCAST, (char *)&broadcast, sizeof(broadcast));
+    setsockopt(temp->sock, SOL_SOCKET, SO_BROADCAST, (const char *)&broadcast, sizeof(broadcast));
 
     /* iOS UDP sockets are weird and apparently can SIGPIPE */
     if (!set_socket_nosigpipe(temp->sock)) {
@@ -659,7 +659,7 @@ Networking_Core *new_networking_ex(Logger *log, IP ip, uint16_t port_from, uint1
         mreq.ipv6mr_multiaddr.s6_addr[ 1] = 0x02;
         mreq.ipv6mr_multiaddr.s6_addr[15] = 0x01;
         mreq.ipv6mr_interface = 0;
-        int res = setsockopt(temp->sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, (char *)&mreq, sizeof(mreq));
+        int res = setsockopt(temp->sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, (const char *)&mreq, sizeof(mreq));
 
         LOGGER_DEBUG(log, res < 0 ? "Failed to activate local multicast membership. (%u, %s)" :
                      "Local multicast group FF02::1 joined successfully", errno, strerror(errno));