The essay analyses how case-law by the Court of Cassation has interpreted the double preliminary doctrine, which the Constitutional Court unexpectedly proposed in judgment no. 269/2017, and subsequently qualified and, to some extent, complicated in 2019 and 2020. The Constitutional Court has no way to force ordinary courts, including the Court of Cassation, to follow the doctrine: they can only be nudged in this direction. The case-law is still sparse and fluctuating. Yet, when the double preliminary doctrine was followed by the Cassation, the Constitutional Court was effectively provided with good occasions to open a dialogue with the Court of Justice, and in almost every case the relevant internal legislation has been annulled definitively and with general effects. In many occasions, the Court of Cassation chose to refer preliminary questions to the Court of Justice, or to disregard internal legislation altogether, directly refusing to apply it: this was correct, as those were not true double preliminary cases.