--- sys/compat/linprocfs/linprocfs.c	(revision 204763)
+++ sys/compat/linprocfs/linprocfs.c	(working copy)
@@ -1312,6 +1312,8 @@
 	    NULL, NULL, NULL, PFS_RD);
 	pfs_create_file(dir, "status", &linprocfs_doprocstatus,
 	    NULL, NULL, NULL, PFS_RD);
+	/* XXX: Hack to make ttyname() work. */
+	pfs_create_file(dir, "fd", NULL, NULL, NULL, NULL, PFS_RD);
 
 	/* /proc/scsi/... */
 	dir = pfs_create_dir(root, "scsi", NULL, NULL, NULL, 0);