In August 1926 and April 1989 the Polish constitutions in force at that time were amended. Substantively these amendments have nothing in common, yet they have many common features, which the author of this article tries to show. In particular, the author draws attention to the fact that they have been used in a way that goes far beyond a formal system correction. The political practice based on them, which differed from the constitutional assumptions, brought fundamental changes in the political system and its evaluation has not been and still is not carried out from the point of view of observance of constitutional standards and the nature of undertaken actions, whether they were aimed to authoritarianism as after May 1926, or to democratization as after April and especially after June 1989.