Async support must be enabled - Aula 14

Tive o seguinte erro após habilitar o processamento assíncrono no controlador. OBS: Sem o retorno Callable funciona normalmente!

HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalStateException: Async support must be enabled on a servlet and for all filters involved in async request processing. This is done in Java code using the Servlet API or by adding "true" to servlet and filter declarations in web.xml.

Seguem os códigos fonte.

PagamentoController.java

package br.com.gbd.alura.controllers;

import br.com.gbd.alura.models.DadosPagamento;
import br.com.gbd.alura.models.CarrinhoCompras;
import br.com.gbd.alura.models.TipoPreco;
import java.util.concurrent.Callable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

/*
    Autor(es): José Carlos de Freitas
    Data: 23/03/2017 às 15:48:16
    Arquivo: PagamentoController
 */
@Controller
@RequestMapping("/pagamento")
public class PagamentoController {

    @Autowired
    CarrinhoCompras carrinho;

    @Autowired
    RestTemplate restTemplate;

    @RequestMapping(value = "/finalizar", method = RequestMethod.POST)
    public Callable<ModelAndView> finalizar(RedirectAttributes redirectAttributes) {
        return () -> {
            try {
                String url = "http://book-payment.herokuapp.com/payment";
                String response = restTemplate.postForObject(url, new DadosPagamento(carrinho.getTotal()), String.class);
                System.out.println(carrinho.getTotal());

                redirectAttributes.addFlashAttribute("msg", response);

                return new ModelAndView("redirect:/produtos");
            } catch (HttpClientErrorException e) {
                e.printStackTrace();
                redirectAttributes.addFlashAttribute("msg", "Valor maior que o permitido");
                return new ModelAndView("redirect:/produtos");
            }
        };
    }

    @RequestMapping("/remover")
    public ModelAndView remover(Integer produtoId, TipoPreco tipoPreco) {
        carrinho.remover(produtoId, tipoPreco);
        return new ModelAndView("redirect:/carrinho");
    }
}

AppWebConfiguration.java

package br.com.gbd.alura.conf;

import br.com.gbd.alura.controllers.HomeController;
import br.com.gbd.alura.daos.ProdutoDAO;
import br.com.gbd.alura.infra.FileSaver;
import br.com.gbd.alura.models.CarrinhoCompras;
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.support.ReloadableResourceBundleMessageSource;
import org.springframework.format.datetime.DateFormatter;
import org.springframework.format.datetime.DateFormatterRegistrar;
import org.springframework.format.support.DefaultFormattingConversionService;
import org.springframework.format.support.FormattingConversionService;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.support.StandardServletMultipartResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

/*
    Autor(es): José Carlos de Freitas
    Data: 05/03/2017 às 10:33:53
    Arquivo: AppWebConfiguration
 */
@EnableWebMvc
@ComponentScan(basePackageClasses = {HomeController.class, ProdutoDAO.class, FileSaver.class, CarrinhoCompras.class})
class AppWebConfiguration extends WebMvcConfigurerAdapter {

    @Bean
    public InternalResourceViewResolver internalResourceViewResolve() {
        InternalResourceViewResolver resolve = new InternalResourceViewResolver();
        resolve.setPrefix("/WEB-INF/jsp/");
        resolve.setSuffix(".jsp");
        resolve.setExposedContextBeanNames("carrinhoCompras");

        return resolve;
    }

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource
                = new ReloadableResourceBundleMessageSource();

        messageSource.setBasename("/WEB-INF/messages");
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setCacheSeconds(1);

        return messageSource;
    }

    @Bean
    public FormattingConversionService mvcConversionService() {
        DefaultFormattingConversionService conversionService = new DefaultFormattingConversionService();
        DateFormatterRegistrar registra = new DateFormatterRegistrar();
        registra.setFormatter(new DateFormatter("dd/MM/yyyy"));
        registra.registerFormatters(conversionService);

        return conversionService;
    }

    @Bean
    public MultipartResolver multipartResolver() {
        return new StandardServletMultipartResolver();
    }

    @Bean
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }
}

Creio que seja um problema de configuração, como o próprio erro descreve, mas não pesquisei muito sobre.