tight loop in kresd 1.3.3 after SIGPIPE

I'm running kresd 1.3.3, I found it was stuck in a tight loop. here's the output of strace:

write(20, "\27\3\3\1\356\0\0\0\0\0\0\0\2H\364\352e\235\t\274\237YF\244\260\250K\223q\211EW"..., 499) = -1 EPIPE (Broken pipe)
--- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=24582, si_uid=110} ---
write(20, "\27\3\3\1\356\0\0\0\0\0\0\0\2H\364\352e\235\t\274\237YF\244\260\250K\223q\211EW"..., 499) = -1 EPIPE (Broken pipe)
--- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=24582, si_uid=110} ---

looking at the open file descriptors with lsof, i see:

kresd   24582 knot-resolver   18ur     REG               0,35      8192   12524 /var/cache/knot-resolver/lock.mdb
kresd   24582 knot-resolver   19u      REG               0,35 104857600   12525 /var/cache/knot-resolver/data.mdb
kresd   24582 knot-resolver   20u     sock                0,8       0t0 4310946 protocol: TCPv6

If i kill and restart the daemon, it will likely work fine again.