diff --git a/CMakeLists.txt b/CMakeLists.txt
index 499a6d53b..554b98eda 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -107,6 +107,7 @@ set(REQUIRED_LIBPORTAL_VERSION 0.8)
 set(REQUIRED_QT_VERSION 6.7.0)
 
 if (WIN32)
+  add_definitions(-DSYSAPI_WIN32 -DWINAPI_MSWINDOWS)
   # VSCMD_ARG_TGT_ARCH is set on CI
   if ("$ENV{VSCMD_ARG_TGT_ARCH}" STREQUAL "")
     # NOT on CI
diff --git a/src/lib/common/Common.h b/src/lib/common/Common.h
index 8487895c2..cfdb6fcad 100644
--- a/src/lib/common/Common.h
+++ b/src/lib/common/Common.h
@@ -7,14 +7,13 @@
 
 #pragma once
 
-#if defined(_WIN32)
-#define SYSAPI_WIN32 1
-#define WINAPI_MSWINDOWS 1
-#elif HAVE_CONFIG_H
+#if !SYSAPI_WIN32
+#if HAVE_CONFIG_H
 #include "Config.h"
 #else
 #error "config.h missing"
 #endif
+#endif
 
 // define nullptr
 #include <stddef.h>