On certain matters to be observed or to be avoided
regarding the Most Holy Eucharist

[59.] The reprobated practice by which Priests, Deacons or the faithful here and there alter or vary at will the texts of the Sacred Liturgy that they are charged to pronounce, must cease. For in doing thus, they render the celebration of the Sacred Liturgy unstable, and not infrequently distort the authentic meaning of the Liturgy.

Got it, gentleman?