java - Spring 4.0 and ActiveMQ enableStompBrokerRelay error

I've successfully got the example running from here using a SimpleBroker.

My config is set up like:

@Override
public void configureMessageBroker(MessageBrokerRegistry registry) {

    registry.enableSimpleBroker("/topic");
    //registry.enableStompBrokerRelay("/queue/","/topic/").setRelayHost("localhost").setRelayPort(61614);
    registry.setApplicationDestinationPrefixes("/app");
}

When I comment out the SimpleBroker and try to use the StompBroker I get the following error.

ERROR: org.springframework.web.servlet.DispatcherServlet - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'stompBrokerRelayMessageHandler' defined in class path resource   [org/springframework/web/socket/config/annotation/DelegatingWebSocketMessageBrokerConfigurat    ion.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.messaging.simp.broker.AbstractBrokerMessageHandler org.springframework.messaging.simp.config.AbstractMessageBrokerConfiguration.stompBrokerRelayMessageHandler()] threw exception; nested exception is java.lang.NoClassDefFoundError: reactor/tcp/encoding/Codec

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:592)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1094)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:989)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)

at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:643)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:606)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:657)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:525)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:466)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:160)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)

at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1088)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5176)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5460)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3954)
at org.apache.catalina.loader.WebappLoader.backgroundProcess(WebappLoader.java:426)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1345)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1530)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)

at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1519)
at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.messaging.simp.broker.AbstractBrokerMessageHandler org.springframework.messaging.simp.config.AbstractMessageBrokerConfiguration.stompBrokerRelayMessageHandler()] threw exception; nested exception is java.lang.NoClassDefFoundError: reactor/tcp/encoding/Codec
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:188)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:581)
... 32 more

Am I missing some resource so that it won't create the bean stompBrokerRelayMessageHandler?

Running this on Tomcat v7.0 inside of STS and using ActiveMQ for the message broker.