bool QTabWidget::hasHeightForWidth() const’ marked override, but does not override

[Ginsengelf]

Hi, I get this error during compilation:

In file included from /usr/include/qt5/QtWidgets/qstyleoption.h:44:0,
                 from /usr/include/qt5/QtWidgets/qabstractitemdelegate.h:38,
                 from /usr/include/qt5/QtWidgets/qabstractitemview.h:40,
                 from /usr/include/qt5/QtWidgets/qheaderview.h:37,
                 from /usr/include/qt5/QtWidgets/QHeaderView:1,
                 from obj/ui/ui_mydialog.h:19
                 (...)
/usr/include/qt5/QtWidgets/qtabwidget.h:120:10: error: ‘bool QTabWidget::hasHeightForWidth() const’ marked override, but does not override
     bool hasHeightForWidth() const Q_DECL_OVERRIDE;

In file included from /usr/include/qt5/QtWidgets/qstyleoption.h:44:0,
                 from /usr/include/qt5/QtWidgets/qabstractitemdelegate.h:38,
                 from /usr/include/qt5/QtWidgets/qabstractitemview.h:40,
                 from /usr/include/qt5/QtWidgets/qheaderview.h:37,
                 from /usr/include/qt5/QtWidgets/QHeaderView:1,
                 from obj/ui/ui_mydialog.h:19
                 (...)
/usr/include/qt5/QtWidgets/qtabwidget.h:120:10: error: ‘bool QTabWidget::hasHeightForWidth() const’ marked override, but does not override
     bool hasHeightForWidth() const Q_DECL_OVERRIDE;

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qtabwidget.h is included by a file generated from an .ui file
I'm using Qt 5.6.1 with g++ 4.8.5 on Linux (openSUSE 42.1)

How can I get rid of this?

Ginsengelf