An injector housing (1) of the injector has an indentation (2) in which a part of an actuator housing (4) of the injector is located. A floor of said indentation (2) is formed by a peripheral support surface (3) for the actuator housing (4). A bottom surface of the actuator housing (4) is oriented towards the support surface (3) and has a peripheral recess (11). This recess (11) is such that the bottom surface of the actuator housing (4) has at least one peripheral projection (12), which is oriented towards the support surface (3) and is adjacent to the support surface (3). A seal (13) for preventing leakage along interfaces between the injector housing (1) and the actuator housing (4) is locate din the recess (11) and is adjacent to the support surface (3).