diff --git a/compat/win32mmap.c b/compat/win32mmap.c
index 61d2ef8e46..80a8c9af4f 100644
--- a/compat/win32mmap.c
+++ b/compat/win32mmap.c
@@ -21,8 +21,8 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
 	if (!(flags & MAP_PRIVATE))
 		die("Invalid usage of mmap when built with USE_WIN32_MMAP");
 
-	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
-		0, 0, 0);
+	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL,
+		PAGE_WRITECOPY, 0, 0, NULL);
 
 	if (!hmap)
 		return MAP_FAILED;