You will need something like this in application.xml or jboss-app.xml but I cant find a concrete docs now:

application.xml

<?xml version="1.0" encoding="UTF-8"?>

<application xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:application="http://java.sun.com/xml/ns/javaee/application_6.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/application_6.xsd" id="Application_ID" version="6">

  <display-name>tx_ear</display-name>

  <initialize-in-order>true</initialize-in-order>

  <module>

    <web>

      <web-uri>tx_admin.war</web-uri>

      <context-root>tx_admin</context-root>

    </web>

  </module>

  <module>

    <web>

      <web-uri>tx_init.war</web-uri>

      <context-root>tx_init</context-root>

    </web>

  </module>

</application>

jboss-app.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE jboss-app  PUBLIC "-//JBoss//DTD Java EE Application 5.0//EN"
  "http://www.jboss.org/j2ee/dtd/jboss-app_5_0.dtd">

<jboss-app>
<module-order>strict</module-order>

</jboss-app>