There are two versions used in Infinispan's pom: 3.23.1-GA used by hibernate-search and 3.24.1-GA apparently used by protostream. But protostream is an uberjar that shades that dependency (although it declares it in pom), so this is not really needed. also, in the past javassist was used by the tools modules for RHQ plugin, but this is no longer the case. I'm tempted to try to remove it for good.