We put the version numbers for Maven plugins inside our `modeshape-parent/pom.xml` file (see [here](https://github.com/ModeShape/modeshape/blob/master/modeshape-parent/pom.xml#L356)]. Please create a property there (e.g., "`jetty.maven.plugin.version`"), and then reference the property here. 

We also put a lot of the default plugin configurations inside the same parent POM, but in this case the plugin configuration is very specific to this module, so I think it's a better idea to specify the configuration here as you've done.