Ошибка при сборки qt

[Stalkert]

Привет.

Добавил класс

#ifndef MYTHREADBALANCER_H
#define MYTHREADBALANCER_H

#include<QThread>

class MyThreadBalancer : public QThread
{
    Q_OBJECT
public:
    explicit MyThreadBalancer(QObject *parent = 0);
    void run();
    bool Stop;
signals:
    void NumberChanged();
public slots:
};

#endif // MYTHREADBALANCER_H

#include "mythreadbalancer.h"
#include<QtCore>

MyThreadBalancer::MyThreadBalancer(QObject *parent) :
   QThread(parent)
{

}


void MyThreadBalancer::run()
{

}

Получаю ошибку при сборки:
error: undefined reference to `vtable for MyThreadBalancer'

 c++, qt