diff --git a/Runtime/CBasicsPC.cpp b/Runtime/CBasicsPC.cpp
index 4d304c6df..2c7f4a579 100644
--- a/Runtime/CBasicsPC.cpp
+++ b/Runtime/CBasicsPC.cpp
@@ -11,7 +11,7 @@
 #include <cstdio>
 #include <cstring>
 #include <ctime>
-#ifdef WIN32
+#ifdef _WIN32
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif
diff --git a/Runtime/CMain.cpp b/Runtime/CMain.cpp
index 69aa4a1ab..ecc5c47d2 100644
--- a/Runtime/CMain.cpp
+++ b/Runtime/CMain.cpp
@@ -4,7 +4,7 @@
 #include <iostream>
 #include "Runtime/CInfiniteLoopDetector.hpp"
 
-#ifdef WIN32
+#ifdef _WIN32
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif