A connection device for connecting a shield conductor of an electrical cable to a grounding section includes: a housing surrounding a receiving space into which an electrical cable is insertable with a shield conductor along a longitudinal axis, the housing being attachable to the grounding section such that the grounding section extends at least partly in the receiving space; and a spring element which is adjustably disposed on the housing and which has a clamping leg and is movable from an open position to a clamped position relative to the housing such that when in the clamped position, the spring element acts with the clamping leg on the shield conductor of the electrical cable inserted in the receiving space, the clamping leg having an engagement portion for acting on the shield conductor, the engagement portion having an at least partially curved or angled engagement contour.