Cannot use JAXB inside a plugin

I need to unmarshal some XML using JAXB.

If I try to add this dependency:

<dependency>
<groupId>com.sun.xml.bind</groupId>
<artifactId>jaxb-xjc</artifactId>
<version>2.2.1</version>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>com.sun.xml.bind</groupId>
<artifactId>jaxb-impl</artifactId>
</exclusion>
</exclusions>
</dependency>

and then to create a JAXB Context:

final JAXBContext context = JAXBContext.newInstance(Model.class);

then I got an exception when launching the plugin:

javax.xml.bind.JAXBException

• with linked exception:
  [java.lang.ClassNotFoundException: com.sun.xml.internal.bind.v2.ContextFactory from [Module "it.xxxxxxx.forge.prova-plugin:1.0.0-SNAPSHOT-c1d512df-2daa-4ebe-ae7a-154e102bb88d" from local module loader @15aaf0b3 (roots: /Applications/sviluppo/jboss/forge-distribution-1.4.0.Final/modules,/Users/ictlm1/.forge/plugins,/Users/ictlm1/Documents/progetti/forge)]]
  at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:187)
  at javax.xml.bind.ContextFinder.find(ContextFinder.java:376)
  at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:574)
  at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:522)
  at it.xxx.forge.parser.Parser.parse(Parser.java:17)
  at it.xxx.forge.forge.CreateEntitiesPlugin.parse(CreateEntitiesPlugin.java:19)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at org.jboss.forge.shell.command.Execution.perform(Execution.java:160)
  ...
  ...
  Caused by: java.lang.ClassNotFoundException: com.sun.xml.internal.bind.v2.ContextFactory from [Module "it.esselunga.forge.prova-plugin:1.0.0-SNAPSHOT-c1d512df-2daa-4ebe-ae7a-154e102bb88d" from local module loader @15aaf0b3 (roots: /Applications/sviluppo/jboss/forge-distribution-1.4.0.Final/modules,/Users/ictlm1/.forge/plugins,/Users/ictlm1/Documents/progetti/forge)]
  at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190)
  at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:468)
  at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:456)
  at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
  at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:120)
  at javax.xml.bind.ContextFinder.safeLoadClass(ContextFinder.java:481)
  at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:185)
  ... 41 more

ContextFactory is part of rt.jar with is bundled with the JDK, how can I tell the ModuleClassLoader to let me load it ??