diff --git a/library/base64.c b/library/base64.c
index e9527db..3b4376d 100644
--- a/library/base64.c
+++ b/library/base64.c
@@ -29,7 +29,7 @@
 
 #include "polarssl/base64.h"
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(EFIX64) && !defined(EFI32)
 #include <basetsd.h>
 typedef UINT32 uint32_t;
 #else