2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/15206We present Arecibo observations of PSR B1534+12 which confirm previous suggestions that the pulse profile is evolving secularly. This effect is similar to that seen in PSR B1913+16, and is almost certainly due to general relativistic precession of the pulsar's spin axis.4 pages, 2 figures. Corrected a reference. To appear in proceedings of IAU Colloquium 177: Pulsar Astronomy - 2000 and BeyondAstrophysicstext