Tensions between the EU’s legal order and the international investment law regime are not exclusive to the Brexit era, but they certainly gained momentum in the aftermath of this referendum. By incautiously declaring that the UK will remain a party to the Unified Patent System regardless of Brexit, the British government arguably shaped (il)legitimate expectations on the part of investors who aimed at exploiting their intellectual property rights in the UK while benefitting from the judicial protection of the forthcoming Unified Patent Court as much as of the European institutions (and market) as a whole. [---]