JBoss EAP 6.4 Jackson module classloading - jboss

Question

I made a small project which looks like this
playboss.ear
lib
commonlib.jar
JsonDeserializer.class
testlib.jar
JsonMessage.class
Version.class
jackson-1.9.4.jar
playboss_ejb.jar
MessageTimer.class
JsonMessage has a member: *private Class msgVersion = Version.V0.class;
MessageTimer is just a Bean with a timeout which does nothing but deserializes an example String of JsonMessage using JsonDeserializer.
Everything works fine, i.e. the String is converted to JsonMessage!
Now I add a dependency to my project containing a JAX-RS API and model objects such that lib is extended.
lib
SomeAPI.jar
javax.ws.rs-api-2.0.jar
Now when I start the JBoss EAP 6.4 I get the following exception:
Caused by: java.lang.ClassNotFoundException: playground.testlib.Version$V0 from [Module "org.codehaus.jackson.jackson-mapper-asl:main" from local module loader #9e89d68
at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:213) [jboss-modules.jar:1.3.7.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:459) [jboss-modules.jar:1.3.7.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:408) [jboss-modules.jar:1.3.7.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:389) [jboss-modules.jar:1.3.7.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:134) [jboss-modules.jar:1.3.7.Final-redhat-1]
at java.lang.Class.forName0(Native Method) [rt.jar:1.8.0_66]
at java.lang.Class.forName(Class.java:264) [rt.jar:1.8.0_66]
at org.codehaus.jackson.map.deser.std.ClassDeserializer.deserialize(ClassDeserializer.java:42) [jackson-mapper-asl-1.9.9.redhat-4.jar:1.9.9.redhat-4]
I figure that due to https://docs.jboss.org/author/display/AS7/Implicit+module+dependencies+for+deployments the jax-rs module dependency is triggered and jackson gets loaded from modules.
My questions:
1) What is the recommended / best way to get my deserialization working again
2) I would like to understand how object mapping is done with jax-rs if the module classloader does obviously not see my model classes.