Because of transitive dependencies, my wars are getting populated by xml-apis, xerces jars. I tried following the instructions on the reference page for maven-war-plugin but it is not working.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
      <packagingExcludes>WEB-INF/lib/xalan-2.6.0.jar,WEB-INF/lib/xercesImpl-2.6.2.jar,WEB-INF/lib/xml-apis-1.0.b2.jar,WEB-INF/lib/xmlParserAPIs-2.6.2.jar</packagingExcludes>
      <webXml>${basedir}/src/main/webapp/WEB-INF/web.xml</webXml>
      <warName>project1</warName>
      <warSourceDirectory>src/main/webapp</warSourceDirectory>
    </configuration>
</plugin>

What am I doing wrong ? If it matters, I discovered that the maven-war-plugin I'm using is at version 2.1-alpha-1