  New high-precision measurements of the longitudinal magnetic field of Ap
stars suggest the existence of secular intrinsic variations of the global
magnetic field in some stars. We argue that such changes are apparent in the Ap
star $\alpha^2$ CVn in the time scale of $\sim$ 10 years, which results from
the analysis of literature data. Therefore, such an observation implies, that
the rate of magnetic field evolution of Ap stars is much higher than was
previously thought.
