diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index be834e2c..4e26d368 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -29,13 +29,8 @@
 #include<ctime>
 
 #ifdef _WIN32
-
-#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #include <Windows.h>
-#undef WIN32_LEAN_AND_MEAN
-#else
-#include <Windows.h>
 #endif 
 
 #endif //_WIN32