A passenger restraint device of a fairground ride passenger unit, which has a passenger space, includes a position-adjustable restraint element and a lockable hydraulic adjuster which acts on the restraint element and has a cylinder-piston unit and a hydraulic accumulator. The hydraulic accumulator and the cylinder-piston unit of the hydraulic adjuster form a structural unit in that the cylinder of the cylinder-piston unit and a cylinder of the hydraulic accumulator arranged next to and parallel to the cylinder are part of an integrated cylinder assembly. The integrated cylinder assembly has a connection block with a switching plate on an axial end face, wherein the hydraulic accumulator is configured as a single unit and is detachably mounted on the switching plate.