[solved] Can't compile with Qt 5.1.1

My problems getting my project up and running from Qt 4.8 to Qt 5.1.1 continue. When I try to compile my program, I get the following error (and 18 others, but this is the first): /usr/local/Qt5.1.1/5.1.1/clang_64/include/QtWidgets/qscrollerproperties.h:56: error: variable has incomplete type ‘class Q_WIDGETS_EXPORT’ class Q_WIDGETS_EXPORT QScrollerProperties I include <QtWidgets> and I added widgets to the QT += line in my .pro file as specified in the guide to transitioning from Qt4.x to Qt5.x am I missing something else? I’m using Qt Creator 2.8.1 on Max OS 10.8 if that helps any.