diff -cr a/src/AboutDialog.h b/src/AboutDialog.h
*** a/src/AboutDialog.h	2018-08-21 20:19:11.097055938 +0300
--- b/src/AboutDialog.h	2018-08-21 20:06:15.323546858 +0300
***************
*** 22,27 ****
--- 22,28 ----
  #define _DIALOGABOUT_H_
  
  #include <QDialog>
+ #include <QAction>
  #include "ui_AboutDialog.h"
  
  class QListWidgetItem;