"Java::JavaLang::IllegalArgumentException: Unexpected message NoticeResponse" error with PostgreSQL 9.6.8

[malcolm-pro]

Getting this error back when trying to connect to PG 9.6.8:

Java::JavaLang::IllegalArgumentException: Unexpected message NoticeResponse
org.jruby.pg.internal.PostgresqlConnection.finishConnecting(PostgresqlConnection.java:1605)
org.jruby.pg.internal.PostgresqlConnection.connectPollInternal(PostgresqlConnection.java:1222)
org.jruby.pg.internal.PostgresqlConnection.connectPoll(PostgresqlConnection.java:170)
org.jruby.pg.internal.PostgresqlConnection.connectDbCommon(PostgresqlConnection.java:1388)
org.jruby.pg.internal.PostgresqlConnection.connectDb(PostgresqlConnection.java:157)
org.jruby.pg.Connection.connectSync(Connection.java:1465)
org.jruby.pg.Connection.initialize(Connection.java:365)
org.jruby.pg.Connection$INVOKER$i$0$0$initialize.call(Connection$INVOKER$i$0$0$initialize.gen)

(lots of non-PG related stack trace available on request)

Not seeing this when connecting to a 9.5 database.

edit As a comparison, I've had no problems connecting with postgres-pr