Depending on your ejb3-core snapshot version, you could be missing the org.jboss.ejb3.iiop.* classes which were moved into the jbossas/ejb3 project, but not included in a build artifact. These are now in the jboss-ejb3-iiop.jar included in the ejb3.deployer commit -m "Put org.jboss.ejb3.iiop.* classes moved from ejb3-core into a jboss-ejb3-iiop.jar included in the ejb3.deployer" /Users/svn/JBossHead/jboss-head/ejb3/build.xml Sending /Users/svn/JBossHead/jboss-head/ejb3/build.xml Transmitting file data ... Committed revision 71909. valkyrie:build starksm$ ls output/jboss-5.0.0.CR1/server/all/deployers/ejb3.deployer/ META-INF jboss-ejb3-deployer.jar jboss-ejb3-iiop.jar