This paper investigates the possibility of avoiding the HEVC intra-frame drift effect induced by additive modifications of the luma DCT/DST coefficients. The main novelty consists in solving the intra-drift problem in its general form: starting from the equations defining the 35 intra-prediction modes and the DCT/DST computation, a mask multiplicative matrix cancelling the intra-frame drift effect is computed. The relevance of the advanced method with respect to the state of the art studies is illustrated, discussed and quantitatively assessed.