  We consider the problem of stabilization to zero of semilinear normal
parabolic equations connected with the 3D Helmholtz system with periodic
boundary conditions and arbitrary initial datum. This problem was previously
studied in \cite{FSh16}. As it was recently revealed, the control function
suggested in that work contains a term impeding transference the stabilization
construction on the 3D Helmholtz system. The main concern of this article is to
prove that this term is not necessary for the stabilization result, and
therefore the control function can be changed by a proper way.
