--- kernel/bsd/isofs/cd9660/iso.h	2018/04/24 18:26:01	1.1
+++ kernel/bsd/isofs/cd9660/iso.h	2018/04/24 18:27:26	1.1.1.2
@@ -283,7 +283,7 @@ int cd9660_sysctl __P((int *, u_int, voi
 
 extern int (**cd9660_vnodeop_p)();
 extern int (**cd9660_specop_p)();
-#ifdef FIFO
+#if FIFO
 extern int (**cd9660_fifoop_p)();
 #endif