diff --git a/backends/fs/windows/windows-fs.cpp b/backends/fs/windows/windows-fs.cpp
index 0b552e275c2..9732efdb6d5 100644
--- a/backends/fs/windows/windows-fs.cpp
+++ b/backends/fs/windows/windows-fs.cpp
@@ -24,6 +24,9 @@
 
 #ifdef WIN32
 
+#if defined(ARRAYSIZE)
+#undef ARRAYSIZE
+#endif
 #include <windows.h>
 // winnt.h defines ARRAYSIZE, but we want our own one...
 #undef ARRAYSIZE