In type-I multiferroics, where ferroelectricity and magnetism arise from different origins, the explicit measurement of magnetoelectric effect is commonly prohibited due to the weak magnetoelectric coupling. From our investigation of magnetic and dielectric properties in a perovskite PbFe0.5Ti0.25W0.25O3, we have directly demonstrated magnetic-field-driven change of dielectric constant in a highly non-linear fashion. Our result offers a potential utilization of magnetoelectric functionality in type-I multiferroics. (C) 2015 Elsevier B.V. All rights reserved.