diff --git a/src/elements/osal.h b/src/elements/osal.h
index cd06271e..f6b5e8c5 100644
--- a/src/elements/osal.h
+++ b/src/elements/osal.h
@@ -118,7 +118,9 @@
 #endif
 
 #if defined(_WIN32) || defined(_WIN64)
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
 #include <tlhelp32.h>
 #include <windows.h>
 #include <winnt.h>