Scaled torque on a migrating (stars/dashed lines) and non-migrating (bullets/solid lines) planet as a function of surface density, Σ₀ and planet mass M. The dotted lines indicate the partially saturated (P11) torques. These show the importance of disc self-gravity correction even for moderate surface density values. We continued the simulations with a non-zero vortensity gradient long enough to have the co-rotation torque established.