<p>The proposal is for a protective device which prevents the unauthorised access to an adjusting or operational component of a fuel supply device, especially a fuel injection pump. The protective device consists of a basic component with a base via which it is screwed to a housing wall of the fuel supply system and a cover (44) which encloses the functional component (25) on the basic component (34) in such a way that the cover has a side wall which is further positively surrounded by a side wall (36) of the basic component. Thus access to the functional component (25) and the securing system of the basic component (34) is prevented. The cover (44) is secured to the basic component by safeguarded fixing means (54).</p>
