Integers being returned as strings

[jkhulme]

activerecord5-redshift-adapter (1.0.1)
activerecord (5.2.4.3)

In our table in redshift we have

Column | Type
member_id  | integer

In the rails console we do

irb(main):004:0> RedshiftDB.connection.raw_connection.async_exec("select member_id from table_name where list_id = $1", [l.id]).column_values(0)
=> ["13615050"]

I would expect this to be an array of integers, not strings, given the type on the column.

Running the same query with a postgres adaptor in a postgres database returns an integer.