Merge pull request #634 from csware/fix-win64-build WIN32 is not always defined, use GIT_WIN32 instead
diff --git a/src/xdiff/xinclude.h b/src/xdiff/xinclude.h
index 2928d32..7d7b77b 100644
--- a/src/xdiff/xinclude.h
+++ b/src/xdiff/xinclude.h
@@ -29,7 +29,7 @@
#include <string.h>
#include <limits.h>
-#ifdef WIN32
+#ifdef GIT_WIN32
#else
#include <unistd.h>
#endif