From what I recall of the syntax, this fragment from kpanelapplet.cpp in kdelibs-3.5.13 *looks* like it's making direct calls into QT3's namespace (not tqtinterface's), even though it doesn't #include any QT files, just TQT stuff: Qt::Orientation KPanelApplet::orientation() const { if( _position == pTop || _position == pBottom ) { return Qt::Horizontal; } else { return Qt::Vertical; } } My understanding is, the QT namespace is included in this code via TQT, allowing the code to compile. If so, this might explain the lengthy linking bug I posted a little while ago (--as-needed does not like transitive dependencies like this). Can someone confirm that this is in fact what is happening? I haven't written a line of C++ code in ~15 years, so I'm not sure I remember how it works. If I'm right, I'll go ahead and file the bug, but I don't want to clutter Bugzilla with non-issues.