Hi all, reading the code it appears the JIRA reporter is right: the static ThreadLocal is using a WeakHashMap but the value is holding a reference to the Configuration, which also happens to be the key. (see SearchConfigurationFromHibernateCore 's constructor, called at line 30 in ContextHolder) So we could make a copy of this configuration object to break the reference, but I would prefer to remove the ThreadLocal completely: assuming we always have the automatic registration in Search 3.1 as it depends on newest Annotations, my proposal is to: 1) In FullTextIndexEventListener.initialize() whe do nothing if already initialized 2) Change EventListenerRegister to always REMOVE whatever additional SearchListener if finds, to make sure there is only one instance. The current EventListenerRegister semantic is not looking safe at the moment anyway: if someone was to register a FullTextIndexEventListener's extension we end up with multiple Search listeners anyway. As there is a TODO in FullTextIndexEventListener to "make it final as soon as FullTextIndexCollectionEventListener is removed" I'd suggest to also 3) make FullTextIndexEventListener final now 4) change the current FullTextIndexCollectionEventListener to a no-op listener, eventually removing/replacing it in EventListenerRegister. And not needed but I think would improve it more: 5A) change the current FullTextIndexEventListener no-arg constructor to do nothing at initialize() to avoid unnecessary processing at startup, in case someone is still declaring it by configuration. 5B) add a 1-arg constructor to it, to be used by EventListenerRegister, so that it's possible at last to have correct final fields in FullTextIndexEventListener to achieve a safe concurrent implementation (EventListenerRegister has a reference to the configuration so can pass it directly to the constructor); IMHO this way the startup would get a nice cleanup: safe for concurrency, no more ThreadLocal worries, no more unused SearchFactories being initialized. what do you think? Sanne