To retain an electric lamp bulb (1), without cement, in a base sleeve (2), nd provide a strain relief for insulated connection leads (6, 7) extending from the lamp, the base is formed of a metallic base sleeve having two opposite side walls (2a, 2b); a base block formed of two parts (3a, 3b) is located within the base sleeve, the parts being essentially F-shaped defining recesses which, when the parts are placed against each other with the recesses facing each other, form through openings (4, 5) within which the electrical connection leads (6, 7) are located. The parts are slightly smaller than the width of the base sleeve, and, upon deformation of the side walls of the base sleeve, for example by forming inwardly projecting dimples (9), the parts are shifted against each other and the insulated electrical connection leads are thereby clamped in the through openings, providing strain relief. Preferably, the region of the parts in the openings is formed with projecting clamping ridges (10, 11) which can further engage with the insulation jacket of the leads (6, 7). The sleeve is made of metal, and the parts of the base block, preferably, of ceramic.