kbase holds multiple KnowledgeBaseEventListenerWrapper instances when adding the same KnowledgeBaseEventListener multiple times ------------------------------------------------------------------------------------------------------------------------------- Key: JBRULES-3666 URL: https://issues.jboss.org/browse/JBRULES-3666 Project: Drools Issue Type: Bug Security Level: Public(Everyone can see) Components: drools-core Affects Versions: 5.5.0.Beta1 Reporter: Toshiya Kobayashi Assignee: Mario Fusco Fix For: 5.5.0.Final When you add the same KnowledgeBaseEventListener to kbase twice, kbase holds both KnowledgeBaseEventListenerWrapper instances. I'm not 100% sure if this is a bug but I guess KnowledgeBaseEventListenerWrapper should implement equals() method like StatefulKnowledgeSessionImpl$AgendaEventListenerWrapper.