Index: sys/fs/fifofs/fifo_vnops.c
===================================================================
--- sys/fs/fifofs/fifo_vnops.c
+++ sys/fs/fifofs/fifo_vnops.c
@@ -73,12 +73,10 @@
 static vop_print_t	fifo_print;
 static vop_open_t	fifo_open;
 static vop_close_t	fifo_close;
-static vop_advlock_t	fifo_advlock;
 
 struct vop_vector fifo_specops = {
 	.vop_default =		&default_vnodeops,
 
-	.vop_advlock =		fifo_advlock,
 	.vop_close =		fifo_close,
 	.vop_create =		VOP_PANIC,
 	.vop_getattr =		VOP_EBADF,
@@ -342,22 +340,3 @@
 	printf("\n");
 	return (0);
 }
-
-/*
- * Fifo advisory byte-level locks.
- */
-/* ARGSUSED */
-static int
-fifo_advlock(ap)
-	struct vop_advlock_args /* {
-		struct vnode *a_vp;
-		caddr_t  a_id;
-		int  a_op;
-		struct flock *a_fl;
-		int  a_flags;
-	} */ *ap;
-{
-
-	return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
-}
-
Index: sys/kern/kern_descrip.c
===================================================================
--- sys/kern/kern_descrip.c
+++ sys/kern/kern_descrip.c
@@ -3096,7 +3096,7 @@
 	error = fget(td, uap->fd, &cap_flock_rights, &fp);
 	if (error != 0)
 		return (error);
-	if (fp->f_type != DTYPE_VNODE) {
+	if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
 		fdrop(fp, td);
 		return (EOPNOTSUPP);
 	}