UHb (broadcast) routes get into OSPF database on OpenBSD 6.4

I have an instance of Bird 1.6.4 on a freshly installed OpenBSD 6.4. My study of its OSPF database shown (with birdc show ospf lsadb self) that there were LSAs for broadcast routes that are indicated as ones having "UHb" in netstat -rn output. I suspect they're added by "protocol direct", but didn't check it yet. Looks like a bug, doesn't it? -- End of message. Next message?