diff --git a/cmake/os.cmake b/cmake/os.cmake
index 44cf56dd..be2368f9 100644
--- a/cmake/os.cmake
+++ b/cmake/os.cmake
@@ -1,4 +1,4 @@
-if (WIN32 OR MINGW)
+if (WIN32 OR CMAKE_SYSTEM_NAME MATCHES "Windows" OR CMAKE_SYSTEM_NAME MATCHES "MSYS" OR CMAKE_SYSTEM_NAME MATCHES "MINGW")
     set(XMRIG_OS_WIN ON)
 elseif (APPLE)
     set(XMRIG_OS_APPLE ON)