Incorrect 'channel' attribute in an endpoint method annotation

@Component
public class MyComponent {}
   @Gateway(requestChannel = "requestChannel", replyChannel = "replyChannel")
   public void gateway() {...}

   @Gateway(
      requestChannel ="simpleBean",   // Bean must be one of these types: org.springframework.integration.MessageChannel,org.springframework.messaging.MessageChannel
      replyChannel = "unknownChannel")   // Cannot find channel
   public void errors() {...}

   @Bean
   public MyBean simpleBean() {...}
}