Check for the presence of _WIN32 rather than its value.
@@ -287,10 +287,10 @@ static int ends_with_dirsep(const char *path)
{
if (*path != '\0')
path += strlen(path) - 1;
-# ifdef __VMS
+# if defined __VMS
if (*path == ']' || *path == '>' || *path == ':')
return 1;
-# elif _WIN32
+# elif defined _WIN32
if (*path == '\\')
return 1;
# endif
