diff --git a/src/crashlog.cpp b/src/crashlog.cpp
index 9582551884..baef530cab 100644
--- a/src/crashlog.cpp
+++ b/src/crashlog.cpp
@@ -610,7 +610,7 @@ bool CrashLog::MakeCrashLog() const
  * information like paths to the console.
  * @return true when everything is made successfully.
  */
-bool CrashLog::MakeDesyncCrashLog() const
+bool CrashLog::MakeDesyncCrashLog(const std::string *log_in, std::string *log_out) const
 {
 	char filename[MAX_PATH];
 	char buffer[65536 * 2];
@@ -624,7 +624,14 @@ bool CrashLog::MakeDesyncCrashLog() const
 	strftime(name_buffer_date, lastof(name_buffer) - name_buffer_date, "%Y%m%dT%H%M%SZ", gmtime(&cur_time));
 
 	printf("Desync encountered (%s), generating desync log...\n", mode);
-	this->FillDesyncCrashLog(buffer, lastof(buffer));
+	char *b = this->FillDesyncCrashLog(buffer, lastof(buffer));
+
+	if (log_in && !log_in->empty()) {
+		b = strecpy(b, "\n", lastof(buffer), true);
+		b = strecpy(b, log_in->c_str(), lastof(buffer), true);
+	}
+
+	if (log_out) log_out->assign(buffer);
 
 	bool bret = this->WriteCrashLog(buffer, filename, lastof(filename), name_buffer);
 	if (bret) {
diff --git a/src/crashlog.h b/src/crashlog.h
index 24ee2d5f67..a7d06c69b2 100644
--- a/src/crashlog.h
+++ b/src/crashlog.h
@@ -128,7 +128,7 @@ public:
 	bool WriteScreenshot(char *filename, const char *filename_last, const char *name = "crash") const;
 
 	bool MakeCrashLog() const;
-	bool MakeDesyncCrashLog() const;
+	bool MakeDesyncCrashLog(const std::string *log_in, std::string *log_out) const;
 	bool MakeCrashSavegameAndScreenshot() const;
 
 	/**
@@ -138,7 +138,7 @@ public:
 	 */
 	static void InitialiseCrashLog();
 
-	static void DesyncCrashLog();
+	static void DesyncCrashLog(const std::string *log_in, std::string *log_out);
 
 	static void SetErrorMessage(const char *message);
 	static void AfterCrashLogCleanup();
diff --git a/src/network/core/os_abstraction.h b/src/network/core/os_abstraction.h
index a8df976d51..5c0a5f2e6b 100644
--- a/src/network/core/os_abstraction.h
+++ b/src/network/core/os_abstraction.h
@@ -62,6 +62,9 @@ typedef unsigned long in_addr_t;
 #	define ioctlsocket ioctl
 #	define closesocket close
 #	define GET_LAST_ERROR() (errno)
+#	define SD_RECEIVE SHUT_RD
+#	define SD_SEND SHUT_WR
+#	define SD_BOTH SHUT_RDWR
 /* Need this for FIONREAD on solaris */
 #	define BSD_COMP
 
@@ -102,6 +105,9 @@ typedef unsigned long in_addr_t;
 #	define ioctlsocket ioctl
 #	define closesocket close
 #	define GET_LAST_ERROR() (sock_errno())
+#	define SD_RECEIVE SHUT_RD
+#	define SD_SEND SHUT_WR
+#	define SD_BOTH SHUT_RDWR
 
 /* Includes needed for OS/2 systems */
 #	include <types.h>
@@ -166,6 +172,21 @@ static inline bool SetNonBlocking(SOCKET d)
 	return ioctlsocket(d, FIONBIO, &nonblocking) == 0;
 }
 
+/**
+ * Try to set the socket into blocking mode.
+ * @param d The socket to set the blocking more for.
+ * @return True if setting the blocking mode succeeded, otherwise false.
+ */
+static inline bool SetBlocking(SOCKET d)
+{
+#ifdef _WIN32
+	u_long nonblocking = 0;
+#else
+	int nonblocking = 0;
+#endif
+	return ioctlsocket(d, FIONBIO, &nonblocking) == 0;
+}
+
 /**
  * Try to set the socket to not delay sending.
  * @param d The socket to disable the delaying for.
@@ -179,6 +200,32 @@ static inline bool SetNoDelay(SOCKET d)
 	return setsockopt(d, IPPROTO_TCP, TCP_NODELAY, (const char*)&b, sizeof(b)) == 0;
 }
 
+
+/**
+ * Try to shutdown the socket in one or both directions.
+ * @param d The socket to disable the delaying for.
+ * @param read Whether to shutdown the read direction.
+ * @param write Whether to shutdown the write direction.
+ * @param linger_timeout The socket linger timeout.
+ * @return True if successful
+ */
+static inline bool ShutdownSocket(SOCKET d, bool read, bool write, uint linger_timeout)
+{
+	if (!read && !write) return true;
+#ifdef _WIN32
+	LINGER ln = { 1U, (uint16) linger_timeout };
+#else
+	struct linger ln = { 1, (int) linger_timeout };
+#endif
+
+	setsockopt(d, SOL_SOCKET, SO_LINGER, (const char*)&ln, sizeof(ln));
+
+	int how = SD_BOTH;
+	if (!read) how = SD_SEND;
+	if (!write) how = SD_RECEIVE;
+	return shutdown(d, how) == 0;
+}
+
 /* Make sure these structures have the size we expect them to be */
 assert_compile(sizeof(in_addr)  ==  4); ///< IPv4 addresses should be 4 bytes.
 assert_compile(sizeof(in6_addr) == 16); ///< IPv6 addresses should be 16 bytes.
diff --git a/src/network/core/tcp_game.cpp b/src/network/core/tcp_game.cpp
index 6d69d10d25..ef3a382219 100644
--- a/src/network/core/tcp_game.cpp
+++ b/src/network/core/tcp_game.cpp
@@ -99,6 +99,7 @@ NetworkRecvStatus NetworkGameSocketHandler::HandlePacket(Packet *p)
 		case PACKET_CLIENT_SET_NAME:              return this->Receive_CLIENT_SET_NAME(p);
 		case PACKET_CLIENT_QUIT:                  return this->Receive_CLIENT_QUIT(p);
 		case PACKET_CLIENT_ERROR:                 return this->Receive_CLIENT_ERROR(p);
+		case PACKET_CLIENT_DESYNC_LOG:            return this->Receive_CLIENT_DESYNC_LOG(p);
 		case PACKET_SERVER_QUIT:                  return this->Receive_SERVER_QUIT(p);
 		case PACKET_SERVER_ERROR_QUIT:            return this->Receive_SERVER_ERROR_QUIT(p);
 		case PACKET_SERVER_SHUTDOWN:              return this->Receive_SERVER_SHUTDOWN(p);
@@ -185,6 +186,7 @@ NetworkRecvStatus NetworkGameSocketHandler::Receive_CLIENT_SET_PASSWORD(Packet *
 NetworkRecvStatus NetworkGameSocketHandler::Receive_CLIENT_SET_NAME(Packet *p) { return this->ReceiveInvalidPacket(PACKET_CLIENT_SET_NAME); }
 NetworkRecvStatus NetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p) { return this->ReceiveInvalidPacket(PACKET_CLIENT_QUIT); }
 NetworkRecvStatus NetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p) { return this->ReceiveInvalidPacket(PACKET_CLIENT_ERROR); }
+NetworkRecvStatus NetworkGameSocketHandler::Receive_CLIENT_DESYNC_LOG(Packet *p) { return this->ReceiveInvalidPacket(PACKET_CLIENT_DESYNC_LOG); }
 NetworkRecvStatus NetworkGameSocketHandler::Receive_SERVER_QUIT(Packet *p) { return this->ReceiveInvalidPacket(PACKET_SERVER_QUIT); }
 NetworkRecvStatus NetworkGameSocketHandler::Receive_SERVER_ERROR_QUIT(Packet *p) { return this->ReceiveInvalidPacket(PACKET_SERVER_ERROR_QUIT); }
 NetworkRecvStatus NetworkGameSocketHandler::Receive_SERVER_SHUTDOWN(Packet *p) { return this->ReceiveInvalidPacket(PACKET_SERVER_SHUTDOWN); }
diff --git a/src/network/core/tcp_game.h b/src/network/core/tcp_game.h
index df0e925f18..03eb5ded44 100644
--- a/src/network/core/tcp_game.h
+++ b/src/network/core/tcp_game.h
@@ -121,6 +121,7 @@ enum PacketGameType {
 	PACKET_SERVER_QUIT,                  ///< A server tells that a client has quit.
 	PACKET_CLIENT_ERROR,                 ///< A client reports an error to the server.
 	PACKET_SERVER_ERROR_QUIT,            ///< A server tells that a client has hit an error and did quit.
+	PACKET_CLIENT_DESYNC_LOG,            ///< A client reports a desync log
 
 	PACKET_END,                          ///< Must ALWAYS be on the end of this list!! (period)
 };
@@ -426,6 +427,7 @@ protected:
 	 * @param p The packet that was just received.
 	 */
 	virtual NetworkRecvStatus Receive_CLIENT_ERROR(Packet *p);
+	virtual NetworkRecvStatus Receive_CLIENT_DESYNC_LOG(Packet *p);
 
 	/**
 	 * Notification that a client left the game:
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index a91a5f90e2..f22e4c3fff 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -174,16 +174,22 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::CloseConnection(NetworkRecvSta
 	 */
 	if (this->sock == INVALID_SOCKET) return status;
 
-	DEBUG(net, 1, "Closed client connection %d", this->client_id);
+	DEBUG(net, 1, "Shutting down client connection %d", this->client_id);
+
+	SetBlocking(this->sock);
 
 	this->SendPackets(true);
 
+	ShutdownSocket(this->sock, false, true, 2);
+
 	/* Wait a number of ticks so our leave message can reach the server.
 	 * This is especially needed for Windows servers as they seem to get
 	 * the "socket is closed" message before receiving our leave message,
 	 * which would trigger the server to close the connection as well. */
 	CSleep(3 * MILLISECONDS_PER_TICK);
 
+	DEBUG(net, 1, "Shutdown client connection %d", this->client_id);
+
 	delete this->GetInfo();
 	delete this;
 
@@ -223,6 +229,8 @@ void ClientNetworkGameSocketHandler::ClientError(NetworkRecvStatus res)
 		SendError(errorno);
 	}
 
+	this->SendPackets();
+
 	ClientNetworkEmergencySave();
 
 	_switch_mode = SM_MENU;
@@ -281,9 +289,11 @@ void ClientNetworkGameSocketHandler::ClientError(NetworkRecvStatus res)
 				NetworkError(STR_NETWORK_ERROR_DESYNC);
 				DEBUG(desync, 1, "sync_err: date{%08x; %02x; %02x}", _date, _date_fract, _tick_skip_counter);
 				DEBUG(net, 0, "Sync error detected!");
-				my_client->ClientError(NETWORK_RECV_STATUS_DESYNC);
 
-				CrashLog::DesyncCrashLog();
+				std::string desync_log;
+				CrashLog::DesyncCrashLog(nullptr, &desync_log);
+				my_client->SendDesyncLog(desync_log);
+				my_client->ClientError(NETWORK_RECV_STATUS_DESYNC);
 				return false;
 			}
 
@@ -469,6 +479,22 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::SendError(NetworkErrorCode err
 	return NETWORK_RECV_STATUS_OKAY;
 }
 
+/** Send an error-packet over the network */
+NetworkRecvStatus ClientNetworkGameSocketHandler::SendDesyncLog(const std::string &log)
+{
+	for (size_t offset = 0; offset < log.size();) {
+		size_t size = min<size_t>(log.size() - offset, SHRT_MAX - 2);
+
+		Packet *p = new Packet(PACKET_CLIENT_DESYNC_LOG);
+		p->Send_uint16(size);
+		p->Send_binary(log.data() + offset, size);
+		my_client->SendPacket(p);
+
+		offset += size;
+	}
+	return NETWORK_RECV_STATUS_OKAY;
+}
+
 /**
  * Tell the server that we like to change the password of the company.
  * @param password The new password.
diff --git a/src/network/network_client.h b/src/network/network_client.h
index 4fc27571b9..25ee42d426 100644
--- a/src/network/network_client.h
+++ b/src/network/network_client.h
@@ -86,6 +86,7 @@ public:
 	static NetworkRecvStatus SendJoin();
 	static NetworkRecvStatus SendCommand(const CommandPacket *cp);
 	static NetworkRecvStatus SendError(NetworkErrorCode errorno);
+	static NetworkRecvStatus SendDesyncLog(const std::string &log);
 	static NetworkRecvStatus SendQuit();
 	static NetworkRecvStatus SendAck();
 
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index 5337eb95f2..0613d47e8a 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -1171,7 +1171,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p
 	NetworkAdminClientError(this->client_id, errorno);
 
 	if (errorno == NETWORK_ERROR_DESYNC) {
-		CrashLog::DesyncCrashLog();
+		CrashLog::DesyncCrashLog(&(this->desync_log), nullptr);
 
 		// have the server and all clients run some sanity checks
 		NetworkSendCommand(0, 0, 0, CMD_DESYNC_CHECK, nullptr, nullptr, _local_company, 0);
@@ -1180,6 +1180,16 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p
 	return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
 }
 
+NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_DESYNC_LOG(Packet *p)
+{
+	uint size = p->Recv_uint16();
+	this->desync_log.resize(this->desync_log.size() + size);
+	p->Recv_binary(const_cast<char *>(this->desync_log.data() + this->desync_log.size() - size), size);
+	DEBUG(net, 2, "Received %u bytes of client desync log", size);
+	this->receive_limit += p->size;
+	return NETWORK_RECV_STATUS_OKAY;
+}
+
 NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p)
 {
 	/* The client wants to leave. Display this and report it to the other
diff --git a/src/network/network_server.h b/src/network/network_server.h
index e985bd535c..89de84d06b 100644
--- a/src/network/network_server.h
+++ b/src/network/network_server.h
@@ -38,6 +38,7 @@ protected:
 	NetworkRecvStatus Receive_CLIENT_SET_NAME(Packet *p) override;
 	NetworkRecvStatus Receive_CLIENT_QUIT(Packet *p) override;
 	NetworkRecvStatus Receive_CLIENT_ERROR(Packet *p) override;
+	NetworkRecvStatus Receive_CLIENT_DESYNC_LOG(Packet *p) override;
 	NetworkRecvStatus Receive_CLIENT_RCON(Packet *p) override;
 	NetworkRecvStatus Receive_CLIENT_NEWGRFS_CHECKED(Packet *p) override;
 	NetworkRecvStatus Receive_CLIENT_MOVE(Packet *p) override;
@@ -75,6 +76,8 @@ public:
 	struct PacketWriter *savegame; ///< Writer used to write the savegame.
 	NetworkAddress client_address; ///< IP-address of the client (so he can be banned)
 
+	std::string desync_log;
+
 	ServerNetworkGameSocketHandler(SOCKET s);
 	~ServerNetworkGameSocketHandler();
 
diff --git a/src/os/macosx/crashlog_osx.cpp b/src/os/macosx/crashlog_osx.cpp
index a70d8acf5b..329f7c50a1 100644
--- a/src/os/macosx/crashlog_osx.cpp
+++ b/src/os/macosx/crashlog_osx.cpp
@@ -516,8 +516,8 @@ void CDECL HandleCrash(int signum, siginfo_t *si, void *context)
 	}
 }
 
-/* static */ void CrashLog::DesyncCrashLog()
+/* static */ void CrashLog::DesyncCrashLog(const std::string *log_in, std::string *log_out)
 {
 	CrashLogOSX log(CrashLogOSX::DesyncTag{});
-	log.MakeDesyncCrashLog();
+	log.MakeDesyncCrashLog(log_in, log_out);
 }
diff --git a/src/os/unix/crashlog_unix.cpp b/src/os/unix/crashlog_unix.cpp
index 9d05a8a087..7883f74b29 100644
--- a/src/os/unix/crashlog_unix.cpp
+++ b/src/os/unix/crashlog_unix.cpp
@@ -620,8 +620,8 @@ static void CDECL HandleCrash(int signum)
 	}
 }
 
-/* static */ void CrashLog::DesyncCrashLog()
+/* static */ void CrashLog::DesyncCrashLog(const std::string *log_in, std::string *log_out)
 {
 	CrashLogUnix log(CrashLogUnix::DesyncTag{});
-	log.MakeDesyncCrashLog();
+	log.MakeDesyncCrashLog(log_in, log_out);
 }
diff --git a/src/os/windows/crashlog_win.cpp b/src/os/windows/crashlog_win.cpp
index 1b4db6d287..8f82cb46d0 100644
--- a/src/os/windows/crashlog_win.cpp
+++ b/src/os/windows/crashlog_win.cpp
@@ -612,10 +612,10 @@ static void CDECL CustomAbort(int signal)
 	SetUnhandledExceptionFilter(ExceptionHandler);
 }
 
-/* static */ void CrashLog::DesyncCrashLog()
+/* static */ void CrashLog::DesyncCrashLog(const std::string *log_in, std::string *log_out)
 {
 	CrashLogWindows log(nullptr);
-	log.MakeDesyncCrashLog();
+	log.MakeDesyncCrashLog(log_in, log_out);
 }
 
 /* The crash log GUI */