Serialize java.time.localdate into json using Jackson

I'm writing a Java 8 Spring MVC application that communicates with a legacy Progress OpenEdge application using a REST service (I'm using Spring's RestTemplate for this). The data I need to read from and write to the Progress application contains some dates. In the Java application, I use a java.time.LocalDate datatype to represent these fields and I'm using Jackson to serialize / deserialize the data into / from Json.

The problem I'm having is the following. When I send data from the Progress Application, the date is send as '2015-01-02' and stored in my Java entity as a LocalDate as expected. When the data is send to the web front-end the Json also contains the date in the same format. When I change information in the web front-end and apply it, it's also send back to the Java application as '2015-01-02' and again stored as a LocalDate without problems. But when I than send the data onwards to the Progress application, the Json I receive doesn't contain the date as '2015-01-02' but as an array containing three fields (2015.0, 1.0, 2.0) and the Progress application is unable to assign this back to a date field in the database.

Offcourse I could write a conversion on the Progress side to convert the array back into a date, but I'd like to avoid this as I would expect the date to always be send in the ISO 8601 format.

According to the information I find on Jackson, a java.time.LocalDate is represented as an array when WRITE_DATES_AS_TIMESTAMPS is enabled, but I have this disabled (And when the date is send to the web front-end, it's not being send as an array...)

Here is some relevant code:

The CustomObjectMapper:

@Service
public class CustomObjectMapper extends ObjectMapper
{
  public CustomObjectMapper()
  {
    this.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS,
                   false);
  }
}

The configuration in my servlet.xml

<mvc:annotation-driven>
  <mvc:message-converters>
    <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
      <property name="objectMapper" ref="customObjectMapper"/>
    </bean>
  </mvc:message-converters>
</mvc:annotation-driven>

<bean id="customObjectMapper" class="com.msoft.utility.CustomObjectMapper"/>

The field definition:

@JsonDeserialize(using = LocalDateDeserializer.class)
@JsonSerialize(using = LocalDateSerializer.class)
private LocalDate deliveryDate;

I'm using Java 8 with Spring 4.1.5 and Jackson 2.5.1.

Any tips how I could get this working or were to search for a solution would be greatly appreciated as I've already been working on this for almost 2 days...

Thanks