Same service-ref-name to different EJB leads to UnsupportedOperationException

Deploying the ejb with following descriptor caused UnsupportedOperationExceptoin:

Caused by: java.lang.UnsupportedOperationException
at org.jboss.as.webservices.webserviceref.WSReferences.add(WSReferences.java:48)
at org.jboss.as.webservices.webserviceref.WSRefDDProcessor.getServiceRef(WSRefDDProcessor.java:88)
at org.jboss.as.webservices.webserviceref.WSRefDDProcessor.processDescriptorEntries(WSRefDDProcessor.java:70)
at org.jboss.as.ee.component.deployers.AbstractDeploymentDescriptorBindingsProcessor.deploy(AbstractDeploymentDescriptorBindingsProcessor.java:103)
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:115) [jboss-as-server-7.1.0.Alpha2-SNAPSHOT.jar:7.1.0.Alpha2-SNAPSHOT]
... 5 more

<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar version="2.1"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/ejb-jar_2_1.xsd">
<display-name>CompTest</display-name>
<enterprise-beans>
<session>
<display-name>HelloClientEjb</display-name>
<ejb-name>HelloClientEjb</ejb-name>
<home>org.jboss.test.ws.HelloClientHome</home>
<remote>org.jboss.test.ws.HelloClientRemote</remote>
<ejb-class>org.jboss.test.ws.HelloClientBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
<service-ref>
<service-ref-name>service/shared_service_ref</service-ref-name>
<service-interface>javax.xml.rpc.Service</service-interface>
<wsdl-file>META-INF/wsdl/HelloService.wsdl</wsdl-file>
<jaxrpc-mapping-file>HelloService.xml</jaxrpc-mapping-file>
<port-component-ref>
<service-endpoint-interface>org.jboss.test.ws.Hello</service-endpoint-interface>
</port-component-ref>
</session>

<session>
<display-name>ByeClientEjb</display-name>
<ejb-name>ByeClientEjb</ejb-name>
<home>org.jboss.test.ws.ByeClientHome</home>
<remote>org.jboss.test.ws.ByeClientRemote</remote>
<ejb-class>org.jboss.test.ws.ByeClientBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
<service-ref>
<service-ref-name>service/shared_service_ref</service-ref-name>
<service-interface>javax.xml.rpc.Service</service-interface>
<wsdl-file>META-INF/wsdl/ByeService.wsdl</wsdl-file>
<jaxrpc-mapping-file>ByeService.xml</jaxrpc-mapping-file>
<port-component-ref>
<service-endpoint-interface>org.jboss.test.ws.Bye</service-endpoint-interface>
</port-component-ref>
</service-ref>
</session>
</enterprise-beans>
</ejb-jar>