bug in paxos(text, text, bigint, text) function?

[Slania]

periodically see this error:

consumer_node_1.rb:19:in `exec': ERROR:  column "proposal_num" does not exist (PG::UndefinedColumn)
LINE 1: SELECT greatest(max(proposal_num), current_proposal_num) + 1
                            ^
QUERY:  SELECT greatest(max(proposal_num), current_proposal_num) + 1
                                         FROM accept_responses
CONTEXT:  PL/pgSQL function paxos(text,text,bigint,text) line 177 at SQL statement
SQL statement "SELECT * FROM paxos(
                    current_proposer_id,
                    current_group_id,
                    current_round_num,
                    proposed_value)"
PL/pgSQL function paxos_apply_and_append(text,text,text) line 18 at SQL statement
SQL statement "SELECT paxos_apply_and_append($1,$2,$3)"
    from consumer_node_1.rb:19:in `execute_job'
    from consumer_node_1.rb:52:in `<main>'

My guess is that https://github.com/citusdata/pg_paxos/blob/master/sql/pg_paxos.sql#L454 should be:
SELECT greatest(max(**min_**proposal_num), current_proposal_num) + 1