if debugPrint {
			fmt.Printf("Mux %d: last pong %v ago, disconnecting\n", m.MuxID, got)
		}
		m.addErrorNonBlockingClose(respHandler, ErrDisconnected)
		return false
	}

	// Send new ping
	err := m.sendLocked(message{Op: OpPing, MuxID: m.MuxID})
	m.respMu.Unlock()
	if err != nil {
		m.addErrorNonBlockingClose(respHandler, err)
	}
	return err == nil
}