Index: head/sys/kern/vfs_vnops.c
===================================================================
--- head/sys/kern/vfs_vnops.c
+++ head/sys/kern/vfs_vnops.c
@@ -2275,9 +2275,13 @@
 		break;
 	case SEEK_DATA:
 		error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
+		if (error == ENOTTY)
+			error = EINVAL;
 		break;
 	case SEEK_HOLE:
 		error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
+		if (error == ENOTTY)
+			error = EINVAL;
 		break;
 	default:
 		error = EINVAL;