diff --git a/acceptor.go b/acceptor.go
index 968be9efb..da4cd9bb0 100644
--- a/acceptor.go
+++ b/acceptor.go
@@ -144,6 +144,13 @@ func (a *Acceptor) Stop() {
 		session.stop()
 	}
 	a.sessionGroup.Wait()
+
+	for sessionID := range a.sessions {
+		err := UnregisterSession(sessionID)
+		if err != nil {
+			return
+		}
+	}
 }
 
 // RemoteAddr gets remote IP address for a given session.
diff --git a/initiator.go b/initiator.go
index 1b48ce4ce..eeff30fc0 100644
--- a/initiator.go
+++ b/initiator.go
@@ -73,7 +73,15 @@ func (i *Initiator) Stop() {
 	default:
 	}
 	close(i.stopChan)
+
 	i.wg.Wait()
+
+	for sessionID := range i.sessionSettings {
+		err := UnregisterSession(sessionID)
+		if err != nil {
+			return
+		}
+	}
 }
 
 // NewInitiator creates and initializes a new Initiator.
diff --git a/session_factory_test.go b/session_factory_test.go
index d14c5b221..349e7580c 100644
--- a/session_factory_test.go
+++ b/session_factory_test.go
@@ -472,6 +472,23 @@ func (s *SessionFactorySuite) TestNewSessionBuildInitiators() {
 	s.Equal("127.0.0.1:5000", session.SocketConnectAddress[0])
 }
 
+func (s *SessionFactorySuite) TestDuplicateSession() {
+	s.sessionFactory.BuildInitiators = true
+	s.SessionSettings.Set(config.HeartBtInt, "34")
+	s.SessionSettings.Set(config.SocketConnectHost, "127.0.0.1")
+	s.SessionSettings.Set(config.SocketConnectPort, "5000")
+
+	session, err := s.createSession(s.SessionID, s.MessageStoreFactory, s.SessionSettings, s.LogFactory, s.App)
+	s.Nil(err)
+	s.True(session.InitiateLogon)
+	_, err = s.createSession(s.SessionID, s.MessageStoreFactory, s.SessionSettings, s.LogFactory, s.App)
+	s.NotNil(err)
+	s.Equal("Duplicate SessionID", err.Error())
+	UnregisterSession(s.SessionID)
+	_, err = s.createSession(s.SessionID, s.MessageStoreFactory, s.SessionSettings, s.LogFactory, s.App)
+	s.Nil(err)
+}
+
 func (s *SessionFactorySuite) TestNewSessionBuildAcceptors() {
 	s.sessionFactory.BuildInitiators = false
 	s.SessionSettings.Set(config.HeartBtInt, "34")