diff --git a/room.go b/room.go
index 7149f46..3458b2f 100644
--- a/room.go
+++ b/room.go
@@ -957,14 +957,8 @@ func (r *Room) NotifySessionChanged(session Session, flags SessionChangeFlag) {
 
 	if flags&SessionChangeInCall != 0 {
 		joinLeave := 0
-		if clientSession, ok := session.(*ClientSession); ok {
-			if clientSession.GetInCall()&FlagInCall != 0 {
-				joinLeave = 1
-			} else {
-				joinLeave = 2
-			}
-		} else if virtual, ok := session.(*VirtualSession); ok {
-			if virtual.GetInCall()&FlagInCall != 0 {
+		if session, ok := session.(SessionWithInCall); ok {
+			if session.GetInCall()&FlagInCall != 0 {
 				joinLeave = 1
 			} else {
 				joinLeave = 2
diff --git a/session.go b/session.go
index 718b8ac..a27efea 100644
--- a/session.go
+++ b/session.go
@@ -76,6 +76,10 @@ type Session interface {
 	SendMessage(message *ServerMessage) bool
 }
 
+type SessionWithInCall interface {
+	GetInCall() int
+}
+
 func parseUserData(data json.RawMessage) func() (api.StringMap, error) {
 	return sync.OnceValues(func() (api.StringMap, error) {
 		if len(data) == 0 {