The Supreme Court of Cyprus in its ruling in Election Petition 1/2019 has for the first time made reference to ‘basic structure’ and ‘unconstitutional constitutional amendments’. The purpose of the article is to assess the rationale of the Court, primarily in internal terms and in relation to its impact on the Cypriot constitutional setting (the internal fit element). From that analysis, the decision of the Court can then be placed in the ongoing debate about ‘unconstitutional constitutional amendments’ and the doctrine of ‘basic structure’ (the external fit element). It is argued that the Court’s approach represents an imperfect fit both in internal and external terms. Moreover, the judicial approach is destabilized by the thin theoretical density attributed to the terms that were used as the foundation for the declaration of the competence for substantive review of amendments to the Constitution. The Court refrained from invalidating the constitutional amendment but proceeded to invalidate the derivative administrative acts, thus applying in a half-way the newly introduced competence.