[Haskell-cafe] Takusen, postgres and boolean fields

Let say one has to do something similar to this: execDML $ cmdbind (sql "update some_table set some_boolean_field = ? where ...") [bindP True, ...] When I do it, I have an error: DBError ("42","804") 7 "ERROR: 42804: column \"some_boolean_field\" is of type boolean but expression is of type text ..." I've noticed that when I read boolean fields from postgres it reads them as string "t" or "f". So I also tried bindP "t" and had same error.