Problem in filtering an optional column in Slick 3.2

QueryOptionalColumn.scala

// ref. https://gist.github.com/cvogt/9193220

// See the example in http://slick.lightbend.com/doc/3.2.1/gettingstarted.html
// I add an optional `buyer` column to Suppliers:
class Suppliers(tag: Tag) extends Table[(Int, String, String, String, String, String, Option[String])](tag, "SUPPLIERS") {
  ...
  def buyer = column[Option[String]]("BUYER")
  ...
}

// Change `=== Option(...)` to `=== Some(...)` cause the following compile error:
suppliers.filter(_.buyer === Option("Martin"))

// [error] DBQueries.scala:32:36: type mismatch;
// [error]  found   : Some[String]
// [error]  required: slick.lifted.Rep[?]
// [error]   suppliers.filter(_.buyer === Some("Martin"))
// [error]                                    ^
// [error] DBQueries.scala:32:19: ambiguous implicit values:
// [error]  both value BooleanCanBeQueryCondition in object CanBeQueryCondition of type => slick.lifted.CanBeQueryCondition[Boolean]
// [error]  and value BooleanOptionColumnCanBeQueryCondition in object CanBeQueryCondition of type => slick.lifted.CanBeQueryCondition[slick.lifted.Rep[Option[Boolean]]]
// [error]  match expected type slick.lifted.CanBeQueryCondition[Nothing]
// [error]   suppliers.filter(_.buyer === Some("Martin"))
// [error]                   ^
// [error] two errors found