replacing 0.0.0.0 listeners at runtime fails

I had DNSPort 0.0.0.0:53 set. Some jerks on the internet started flooding me with DNS requests so I reconfigured tor to only have the DNSPort on my LAN interface. I sent tor a HUP to reload the config, and it exited because it tried to bind the new listener before unbinding the old one:

Dec 16 16:19:51.000 [notice] Opening DNS listener on 172.16.0.1:53
Dec 16 16:19:51.000 [warn] Could not bind to 172.16.0.1:53: Permission denied
Dec 16 16:19:51.000 [notice] Closing no-longer-configured DNS listener on 0.0.0.0:53
Dec 16 16:19:51.000 [warn] Failed to parse/validate config: Failed to bind one of the listener ports.
Dec 16 16:19:51.000 [err] Reading config failed--see warnings above. For usage, try -h.
Dec 16 16:19:51.000 [warn] Restart failed (config error?). Exiting.