This paper critically reexamines the jurisprudence of “legal forms” of the Slovak Constitutional Court and the corresponding possibility for an unconstitutional constitutional amendment decision. The Court traditionally held back from reviewing constitutional amendments, despite sporadic dicta in the case-law that if a challenged act constituted an abuse of form, it would need to do so. The paper reviews Slovak domestic theory on the unconstitutional constitutional amendments and assesses the recent developments wrought by the decision in the Amnesty Abolition Case PL. ÚS 7/2017, where the Court for the first time comprehensively charted the material core of the Constitution. The paper also draws a comparison to the Czech Melčák Case (Pl. ÚS 27/09) of an unconstitutional act.