On a proper construction of Article 1(a) of Council Directive 93/37/EEC of 14 June 1993 concerning the coordination of procedures for the award of public works contracts, where the main object of a contract is the execution of a work corresponding to the requirements expressed by the contracting authority, that contract constitutes a public works contract and is not, therefore, covered by the exclusion referred to in Article 1(a)(iii) of Council Directive 92/50/EEC of 18 June 1992 relating to the coordination of procedures for the award of public service contracts, even if it contains an undertaking to let the work in question. To the extent that it is authorised to do so by the applicable domestic rules of procedure, a national court – such as the referring court – which has given a ruling at last instance, without a reference having first been made to the Court of Justice of the European Union under Article 267 TFEU, that has led to a situation which is incompatible with the EU legislation on public works contracts must either supplement or go back on that definitive ruling so as to take into account any interpretation of that legislation provided by the Court subsequently.