The ObjectMapperBundle configures the Jackson ObjectMapper used by Dropwizard for serializing and deserializing all responses, as well as for logging by bundles such as liftwizard-bundle-logging-config . ObjectMapperBundle supports configuring pretty-printing on or off, and serialization inclusion to any value in Jackson's JsonInclude.Include . ObjectMapperBundle also turns on all json5 features, turns on FAIL_ON_UNKNOWN_PROPERTIES , turns on STRICT_DUPLICATE_DETECTION , and turns on serialization of dates and Strings.To turn it on, add ObjectMapperBundle to the list of registered bundles. java @Override public void initialize(Bootstrap<HelloWorldConfiguration> bootstrap) { // JsonConfigurationFactoryFactory uses a separate ObjectMapper, and can be configured earlier bootstrap.setConfigurationFactoryFactory(new JsonConfigurationFactoryFactory<>()); bootstrap.addBundle(new EnvironmentConfigBundle()); bootstrap.addBundle(new ObjectMapperBundle()); // ConfigLoggingBundle uses the ObjectMapper configured by ObjectMapperBundle bootstrap.addBundle(new ConfigLoggingBundle()); // ... } You'll be able to see that ObjectMapperBundle is working because the output of ConfigLoggingBundle will now be pretty-printed by default. ObjectMapperBundle lives in the liftwizard-bundle-object-mapper module. xml <dependency> <groupId>io.liftwizard</groupId> <artifactId>liftwizard-bundle-object-mapper</artifactId> </dependency>