Hi, Is it enough to define: QMAKE_CFLAGS -= -arch:AVX -arch:AVX2 QMAKE_CXXFLAGS -= -arch:AVX -arch:AVX2 to ensure that compilation by QtCreator with Qt-5.14-MSVC Windows will not compile with such optimization flags even if avx and avx2 instructions have not been disabled in Qt-library itself? Thanks! Kind regards, Robert