We show that electrically poled ferroelectric matrix considerably enhances the localized magnetostrictive deformations in a ferroelectric-ferrimagnetic composite. Magnetostrain measurements performed on Dy-free and Dy-modified BiFeO3-PbTiO3 (BF-PT) ferroelectric ceramics revealed no measurable macroscopic strain in poled and unpoled Dy-free nonferromagnetic specimens. Dy-modified BF-PT, on the other hand, exhibit ferrimagnetic dysprosium-iron garnet (DyIG) as precipitates and exhibit a macroscopic strain of -4 ppm in the poled state. Despite the small (6%) volume fraction of DyIG, the macroscopic strain in Dy-modified BF-PT is almost 50% of the strain of pure DyIG. Our results suggest that the amplification of the localized magnetostrictive deformation in the ferrimagnetic islands by the neighboring ferroelectric regions is caused by the magnetostrictive stress-induced motion of ferroelectric-ferroelastic domains of the poled ferroelectric matrix. © 2021 American Physical Society.