diff --git a/include/mgba-util/common.h b/include/mgba-util/common.h
index c5008e01f..04018faf4 100644
--- a/include/mgba-util/common.h
+++ b/include/mgba-util/common.h
@@ -17,7 +17,9 @@
 CXX_GUARD_START
 
 #ifdef _WIN32
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
 // Require Windows 7 or newer
 #ifndef _WIN32_WINNT
 #define _WIN32_WINNT 0x0601