The disclosure relates to a telescopic support prop, which has a leg with a lower leg part and an upper leg part. The upper leg part has a plurality of vertically spaced through holes. A locking pin is releasably connected to one of the vertically spaced through holes of the upper leg part. A cap is connected to the locking pin, the cap having a fastening sleeve put over an end of the locking pin, the cap further having a spring for bearing against the exterior of the lower leg part.