diff --git a/win/share/tile2bmp.c b/win/share/tile2bmp.c
index 434ab694f..cfcc1c01e 100644
--- a/win/share/tile2bmp.c
+++ b/win/share/tile2bmp.c
@@ -36,7 +36,7 @@ extern void objects_globals_init(void);
 # endif
 #endif
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && defined(_WIN64)
 #define UNALIGNED_POINTER __unaligned
 #else
 #define UNALIGNED_POINTER