JBoss 6.0.0.Final: EJBs in a WAR don't work

Accessing a JAX-RS resource with the @Stateless annotation in the web module fails with the following exception:

javax.naming.NameNotFoundException: local not bound
org.jnp.server.NamingServer.getBinding(NamingServer.java:771)
org.jnp.server.NamingServer.getBinding(NamingServer.java:779)
org.jnp.server.NamingServer.getObject(NamingServer.java:785)
org.jnp.server.NamingServer.lookup(NamingServer.java:443)
org.jnp.server.NamingServer.lookup(NamingServer.java:399)
org.jnp.server.NamingServer.lookup(NamingServer.java:399)
org.jnp.interfaces.NamingContext.lookup(NamingContext.java:728)
org.jnp.interfaces.NamingContext.lookup(NamingContext.java:688)
javax.naming.InitialContext.lookup(InitialContext.java:392)
org.jboss.resteasy.plugins.server.resourcefactory.JndiComponentResourceFactory.createResource(JndiComponentResourceFactory.java:53)
org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:205)
org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:503)
org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:480)
org.jboss.resteasy.core.SynchronousDispatcher.invokePropagateNotFound(SynchronousDispatcher.java:139)
org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:211)
org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.doFilter(FilterDispatcher.java:59)

The bean:

import javax.ejb.Stateless;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.SecurityContext;

@Produces("application/xml")
@Path("foo")
@Stateless
public class Iets {

@GET
@Path("bar")
public String getTest()

{ return "<test>test</test>"; }

}

Because it's a Java EE 6 environment, I did not configure anything in web.xml.