diff --git a/acceptor.go b/acceptor.go
index 98db720..be3ae1a 100644
--- a/acceptor.go
+++ b/acceptor.go
@@ -69,7 +69,7 @@ func (w *WebSocketAcceptor) Spec(subProtocol string) (serializers.Serializer, er
 	return serializer, nil
 }
 
-func (w *WebSocketAcceptor) Accept(conn net.Conn, config *WebSocketServerConfig) (BaseSession, error) {
+func (w *WebSocketAcceptor) Accept(conn net.Conn, router *Router, config *WebSocketServerConfig) (BaseSession, error) {
 	if config == nil {
 		config = DefaultWebSocketServerConfig()
 	}
@@ -90,6 +90,19 @@ func (w *WebSocketAcceptor) Accept(conn net.Conn, config *WebSocketServerConfig)
 		return nil, fmt.Errorf("")
 	}
 
+	if !router.HasRealm(hello.Realm()) {
+		abortMessage := messages.NewAbort(map[string]any{}, wampproto.ErrNoSuchRealm, nil, nil)
+		serializedAbort, err := serializer.Serialize(abortMessage)
+		if err != nil {
+			return nil, fmt.Errorf("failed to serialize abort: %w", err)
+		}
+		if err = peer.Write(serializedAbort); err != nil {
+			return nil, fmt.Errorf("failed to send abort: %w", err)
+		}
+
+		return nil, fmt.Errorf(wampproto.ErrNoSuchRealm)
+	}
+
 	return Accept(peer, hello, serializer, w.Authenticator)
 }
 
diff --git a/acceptor_test.go b/acceptor_test.go
index 68a7b52..7e8011a 100644
--- a/acceptor_test.go
+++ b/acceptor_test.go
@@ -24,8 +24,11 @@ func TestAccept(t *testing.T) {
 		require.NoError(t, err)
 		require.NotNil(t, conn)
 
+		rout := xconn.NewRouter()
+		rout.AddRealm("realm1")
+
 		acceptor := xconn.WebSocketAcceptor{}
-		session, err := acceptor.Accept(conn, nil)
+		session, err := acceptor.Accept(conn, rout, nil)
 		require.NoError(t, err)
 		require.NotNil(t, session)
 
diff --git a/server.go b/server.go
index c848cd3..ded9707 100644
--- a/server.go
+++ b/server.go
@@ -64,7 +64,7 @@ func (s *Server) HandleClient(conn net.Conn) {
 	config := DefaultWebSocketServerConfig()
 	config.KeepAliveInterval = s.keepAliveInterval
 	config.KeepAliveTimeout = s.keepAliveTimeout
-	base, err := s.acceptor.Accept(conn, config)
+	base, err := s.acceptor.Accept(conn, s.router, config)
 	if err != nil {
 		return
 	}