diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b686e6e4..0f1db8c31 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -103,7 +103,7 @@ set(REQUIRED_LIBPORTAL_VERSION 0.9.1)
 set(REQUIRED_QT_VERSION 6.7.0)
 
 if (WIN32)
-  add_definitions(-DSYSAPI_WIN32 -DWINAPI_MSWINDOWS)
+  add_definitions(-DWINAPI_MSWINDOWS)
   # VSCMD_ARG_TGT_ARCH is set on CI
   if ("$ENV{VSCMD_ARG_TGT_ARCH}" STREQUAL "")
     # NOT on CI
diff --git a/src/apps/deskflow-core/deskflow-core.cpp b/src/apps/deskflow-core/deskflow-core.cpp
index f4601b1c0..052b380e8 100644
--- a/src/apps/deskflow-core/deskflow-core.cpp
+++ b/src/apps/deskflow-core/deskflow-core.cpp
@@ -16,7 +16,7 @@
 #include "deskflow/ClientApp.h"
 #include "deskflow/ServerApp.h"
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchMiscWindows.h"
 #include <QCoreApplication>
 #endif
@@ -32,7 +32,7 @@ void showHelp(const CoreArgParser &parser)
 
 int main(int argc, char **argv)
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   // HACK to make sure settings gets the correct qApp path
   QCoreApplication m(argc, argv);
   m.deleteLater();
diff --git a/src/apps/deskflow-daemon/DaemonApp.cpp b/src/apps/deskflow-daemon/DaemonApp.cpp
index a0e392e24..ce317a3cd 100644
--- a/src/apps/deskflow-daemon/DaemonApp.cpp
+++ b/src/apps/deskflow-daemon/DaemonApp.cpp
@@ -15,8 +15,7 @@
 #include "common/Settings.h"
 #include "deskflow/ipc/DaemonIpcServer.h"
 
-#if SYSAPI_WIN32
-
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchDaemonWindows.h"
 #include "deskflow/Screen.h"
 #include "platform/MSWindowsDebugOutputter.h"
@@ -64,7 +63,7 @@ void DaemonApp::applyWatchdogCommand() const
 {
   LOG_DEBUG("applying watchdog command");
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   m_pWatchdog->setProcessConfig(m_command, m_elevate);
 #else
   LOG_ERR("applying watchdog command not implemented on this platform");
@@ -78,7 +77,7 @@ void DaemonApp::clearWatchdogCommand()
   // Clear the setting to prevent it from being next time the daemon starts.
   setCommand("");
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   m_pWatchdog->setProcessConfig("", false);
 #else
   LOG_ERR("clearing watchdog command not implemented on this platform");
@@ -137,7 +136,7 @@ void DaemonApp::run(QThread &daemonThread)
     LOG_DEBUG("daemon thread finished");
   });
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   m_pWatchdog = std::make_unique<MSWindowsWatchdog>(m_foreground, *m_pFileLogOutputter);
 
   auto command = Settings::value(Settings::Daemon::Command).toString().toStdString();
@@ -154,7 +153,7 @@ void DaemonApp::run(QThread &daemonThread)
 
 int DaemonApp::daemonLoop()
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   // Runs the daemon through the Windows service controller, which controls the program lifecycle.
   return ArchDaemonWindows::runDaemon([this]() { return mainLoop(); });
 #else
@@ -164,7 +163,7 @@ int DaemonApp::daemonLoop()
 
 int DaemonApp::mainLoop()
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   if (m_pWatchdog == nullptr) {
     LOG_ERR("watchdog not initialized");
     return s_exitFailed;
@@ -173,7 +172,7 @@ int DaemonApp::mainLoop()
 #endif
 
   try {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
     // Install the platform event queue to handle service stop events.
     // This must be done on the same thread as the event loop, otherwise the service stop
     // request will not add the quit event to the event queue, and the service won't stop.
@@ -193,7 +192,7 @@ int DaemonApp::mainLoop()
 
   LOG_INFO("daemon is stopping");
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   try {
     LOG_DEBUG("stopping process watchdog");
     m_pWatchdog->stop();
@@ -221,7 +220,7 @@ void DaemonApp::setForeground()
 
 void DaemonApp::initLogging()
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   if (!m_foreground) {
     // Only use MS debug outputter when the process is daemonized, since stdout won't be accessible
     // in that case, but is accessible when running in the foreground.
@@ -235,7 +234,7 @@ void DaemonApp::initLogging()
 
 void DaemonApp::showConsole()
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   // The daemon bin is compiled using the Win32 subsystem which works best for Windows services,
   // so when running as a foreground process we need to allocate a console (or we won't see output).
   // It is important to do this inside the arg check loop so that we can attach console ahead
diff --git a/src/apps/deskflow-daemon/DaemonApp.h b/src/apps/deskflow-daemon/DaemonApp.h
index da18bb416..ca9a250fa 100644
--- a/src/apps/deskflow-daemon/DaemonApp.h
+++ b/src/apps/deskflow-daemon/DaemonApp.h
@@ -21,7 +21,7 @@ namespace deskflow::core::ipc {
 class DaemonIpcServer;
 }
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 class MSWindowsWatchdog;
 #endif
 
@@ -56,7 +56,7 @@ private:
 
   static void showConsole();
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   std::unique_ptr<MSWindowsWatchdog> m_pWatchdog;
 #endif
 
diff --git a/src/apps/deskflow-daemon/deskflow-daemon.cpp b/src/apps/deskflow-daemon/deskflow-daemon.cpp
index 8d03f2084..ac0c0e513 100644
--- a/src/apps/deskflow-daemon/deskflow-daemon.cpp
+++ b/src/apps/deskflow-daemon/deskflow-daemon.cpp
@@ -15,13 +15,11 @@
 #include "common/VersionInfo.h"
 #include "deskflow/ipc/DaemonIpcServer.h"
 
-#if SYSAPI_WIN32
-
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchMiscWindows.h"
 
 #define WIN32_LEAN_AND_MEAN
 #include <Windows.h>
-
 #endif
 
 #include <QCommandLineParser>
@@ -34,7 +32,7 @@ void handleError(const char *message = "Unrecognized error.");
 
 int main(int argc, char **argv)
 {
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   ArchMiscWindows::guardRuntimeVersion();
 
   // Save window instance for later use, e.g. `GetModuleFileName` which is used when installing the daemon.
@@ -85,7 +83,7 @@ int main(int argc, char **argv)
 
   try {
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
     // Show warning if not running as admin as daemon will behave differently.
     if (!ArchMiscWindows::isProcessElevated()) {
       LOG_WARN("not running as admin, some features may not work");
@@ -115,8 +113,7 @@ int main(int argc, char **argv)
   }
 }
 
-#if SYSAPI_WIN32
-
+#if defined(Q_OS_WIN)
 // Win32 subsystem entry point (simply forwards to main).
 // We need this because using regular main under the Win32 subsystem results in empty args.
 int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
@@ -131,7 +128,7 @@ void handleError(const char *message)
   // Always print error to stdout in case run as CLI program.
   LOG_ERR("%s", message);
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   // Show a message box for when run from MSI in Win32 subsystem.
   MessageBoxA(nullptr, message, "Deskflow daemon error", MB_OK | MB_ICONERROR);
 #endif
diff --git a/src/lib/arch/Arch.cpp b/src/lib/arch/Arch.cpp
index 47319ce47..6544f9ebf 100644
--- a/src/lib/arch/Arch.cpp
+++ b/src/lib/arch/Arch.cpp
@@ -10,7 +10,7 @@
 
 #include <thread>
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchMiscWindows.h"
 #endif
 
@@ -26,7 +26,7 @@ Arch::Arch()
   s_instance = this;
 }
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 void Arch::init()
 {
   ARCH_NETWORK::init();
diff --git a/src/lib/arch/Arch.h b/src/lib/arch/Arch.h
index 6c88f177b..ddf24e896 100644
--- a/src/lib/arch/Arch.h
+++ b/src/lib/arch/Arch.h
@@ -5,7 +5,7 @@
  * SPDX-FileCopyrightText: (C) 2002 Chris Schoeneman
  * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
  */
-
+#include <QtSystemDetection>
 // Consider whether or not to use either encapsulation (as below)
 // or inheritance (as it is now) for the ARCH stuff.
 //
@@ -25,20 +25,16 @@
 
 #pragma once
 
-#if SYSAPI_WIN32
-
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchDaemonWindows.h"
 #include "arch/win32/ArchLogWindows.h"
 #include "arch/win32/ArchMultithreadWindows.h"
 #include "arch/win32/ArchNetworkWinsock.h"
-
 #else
-
 #include "arch/ArchDaemonNone.h"
 #include "arch/unix/ArchLogUnix.h"
 #include "arch/unix/ArchMultithreadPosix.h"
 #include "arch/unix/ArchNetworkBSD.h"
-
 #endif
 
 /*!
@@ -63,7 +59,7 @@ public:
   Arch();
   ~Arch() override = default;
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   //! Call init on other arch classes.
   /*!
   Some arch classes depend on others to exist first. When init is called
diff --git a/src/lib/deskflow/App.cpp b/src/lib/deskflow/App.cpp
index ae430b417..dd5a89c13 100644
--- a/src/lib/deskflow/App.cpp
+++ b/src/lib/deskflow/App.cpp
@@ -16,7 +16,7 @@
 #include "common/Settings.h"
 #include "deskflow/DeskflowException.h"
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 #include "base/IEventQueue.h"
 #endif
 
diff --git a/src/lib/deskflow/App.h b/src/lib/deskflow/App.h
index 18b138c8b..52baded3f 100644
--- a/src/lib/deskflow/App.h
+++ b/src/lib/deskflow/App.h
@@ -13,7 +13,7 @@
 #include "deskflow/IApp.h"
 #include "net/SocketMultiplexer.h"
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 #include "deskflow/win32/AppUtilWindows.h"
 #else
 #include "deskflow/unix/AppUtilUnix.h"
diff --git a/src/lib/deskflow/ServerApp.cpp b/src/lib/deskflow/ServerApp.cpp
index c85cb3cea..ed4418ca6 100644
--- a/src/lib/deskflow/ServerApp.cpp
+++ b/src/lib/deskflow/ServerApp.cpp
@@ -116,7 +116,7 @@ bool ServerApp::loadConfig(const QString &filename)
   try {
     // load configuration
     LOG_DEBUG("opening configuration \"%s\"", path.c_str());
-#ifdef SYSAPI_WIN32
+#if defined(Q_OS_WIN)
     std::ifstream configStream(filename.toStdWString());
 #else
     std::ifstream configStream(path);
diff --git a/src/lib/net/SecureSocket.cpp b/src/lib/net/SecureSocket.cpp
index 326074e4f..0b71b7a47 100644
--- a/src/lib/net/SecureSocket.cpp
+++ b/src/lib/net/SecureSocket.cpp
@@ -658,7 +658,7 @@ ISocketMultiplexerJob *SecureSocket::serviceConnect(ISocketMultiplexerJob *const
   Lock lock(&getMutex());
 
   int status = 0;
-#ifdef SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   status = secureConnect(static_cast<int>(getSocket()->m_socket));
 #else
   status = secureConnect(getSocket()->m_fd);
@@ -686,7 +686,7 @@ ISocketMultiplexerJob *SecureSocket::serviceAccept(ISocketMultiplexerJob *const,
   Lock lock(&getMutex());
 
   int status = 0;
-#ifdef SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   status = secureAccept(static_cast<int>(getSocket()->m_socket));
 #else
   status = secureAccept(getSocket()->m_fd);
diff --git a/src/lib/net/SecureUtils.cpp b/src/lib/net/SecureUtils.cpp
index 65aa74803..bc820a723 100644
--- a/src/lib/net/SecureUtils.cpp
+++ b/src/lib/net/SecureUtils.cpp
@@ -92,7 +92,7 @@ void generatePemSelfSignedCert(const QString &path, int keyLength)
   X509_sign(cert, privateKey, EVP_sha256());
 
   const std::filesystem::path fsPath = path.toStdString();
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   auto fp = _wfopen(fsPath.native().c_str(), L"w");
 #else
   auto fp = std::fopen(fsPath.native().c_str(), "w");
diff --git a/src/unittests/legacytests/legacytests/main.cpp b/src/unittests/legacytests/legacytests/main.cpp
index e718bd638..cd311b26a 100644
--- a/src/unittests/legacytests/legacytests/main.cpp
+++ b/src/unittests/legacytests/legacytests/main.cpp
@@ -9,7 +9,7 @@
 #include "base/Log.h"
 #include "unittests/legacytests/shared/ExitTimeout.h"
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
 #include "arch/win32/ArchMiscWindows.h"
 #endif
 
@@ -23,7 +23,7 @@ int main(int argc, char **argv)
 {
   ExitTimeout exitTimeout(1, "Unit tests");
 
-#if SYSAPI_WIN32
+#if defined(Q_OS_WIN)
   // HACK: shouldn't be needed, but logging fails without this.
   ArchMiscWindows::setInstanceWin32(GetModuleHandle(nullptr));
 #endif