The unitary patent package is shielded against external judicial review in multiple ways. The norms providing the unitary patent its substantive contents, the Agreement on a Unified Patent Court (AUPC) and the European Patent Convention (EPC), are largely shielded from judicial review. European Patent Office (EPO) decisions cannot be subjected to direct scrutiny before EU courts either. Whereas the unitary patent and EPC systems will likely converge based on shared expert rule, EU law is at the same time subjected to fragmentation. Its core principles concerning legality and judicial review are being undermined in the process. However, through the preliminary ruling procedure, general EU norms and legal principles may still affect the package considerably more than envisioned by the architects thereof. Moreover, Brexit will require re-opening the package, and might open a window of opportunity for a political process leading to an improved design mending the current systemic defects.