The invention relates to a system (1) and to a corresponding method for tank leakage diagnosis. The system (1) comprises a fuel tank (3), a pressure source (5, 9), and a pressure sensor (7). The pressure source (5, 9) is configured to increase the pressure in the fuel tank (3). The pressure sensor (7) is configured to detect the pressure progression at the fuel tank (3). The system (1) is configured to seal the fuel tank (3) in a gas-tight manner such that the fuel tank (3) can be used as a pressure store. Furthermore, the system (1) is configured to conclude, independently of a current operation of the pressure source (5, 9) based on the determined pressure progression at the fuel tank (3), that a leak is present.